OF  THE 

UNIVERSITY 

OF 


LIBRARY 


SMITHSONIAN  INSTITUTION 

UNITED  STATES  NATIONAL  MUSEUM 
Bulletin  88 


REVISION   OF   PALEOZOIC    STELLEROIDEA 

WITH  SPECIAL  REFERENCE  TO  NORTH 

AMERICAN  ASTEROIDEA 


BY 


CHARLES  SCHUCHERT 

Professor  of  Paleontology,  Yale  University 
Sew  Haven 


WASHINGTON 

GOVERNMENT  PRINTING  OFFICE 
1915 


SMITHSONIAN  INSTITUTION 

UNITED  STATES  NATIONAL  MUSEUM 
Bulletin  88 


REVISION   OF   PALEOZOIC    STELLEROIDEA 

WITH  SPECIAL  REFERENCE  TO  NORTH 

AMERICAN  ASTEROIDEA 


BY 


'•  '*" 


CHARLES  SCHUCHERT 

Professor  of  Paleontology ,  Yale  University 
New  Haven 


WASHINGTON 

GOVERNMENT  PRINTING  OFFICE 
1915 


PALEONTOLOGY 

BULLETIN  OF  THE  UNITED  STATES  NATIONAL  MUSEUM. 
ISSUED  MARCH  20,  1915. 


ADVERTISEMENT. 

The  scientific  publications  of  the  United  States  National  Museum 
consist  of  two  series,  the  Proceedings  and  the  Bulletins. 

The  Proceedings,  the  first  volume  of  which  was  issued  in  1878,  are 
intended  primarily  as  a  medium  for  the  publication  of  original,  and 
usually  brief,  papers  based  on  the  collections  of  the  National  Museum, 
presenting  newly-acquired  facts  in  zoology,  geology,  and  anthro- 
pology, including  descriptions  of  new  forms  of  animals,  and  revisions 
of  limited  groups.  One  or  two  volumes  are  issued  annually  and  dis- 
tributed to  libraries  and  scientific  organizations.  A  limited  number 
of  copies  of  each  paper,  in  pamphlet  form,  is  distributed  to  specialists 
and  others  interested  in  "the  different  subjects  as  soon  as  printed. 
The  date  of  publication  is  printed  on  each  paper,  and  these  dates  are 
also  recorded  in  the  tables  of  contents  of  the  volumes. 

The  Bulletins,  the  first  of  which  was  issued  in  1875,  consist  of  a 
series  of  separate  publications  comprising  chiefly  monographs  of  large 
zoological  groups  and  other  general  systematic  treatises  (occasionally 
in  several  volumes),  faunal  works,  reports  of  expeditions,  and  cata- 
logues of  type-specimens,  special  collections,  etc.  The  majority  of 
the  volumes  are  octavos,  but  a  quarto  size  has  been  adopted  in  a  few 
instances  in  which  large  plates  were  regarded  as  indispensable. 

Since  1902  a  series  of  octavo  volumes  containing  papers  relating  to 
the  botanical  collections  of  the  "Museum,  and  known  as  the  Contribu- 
tions from  the  National  Herbarium,  has  been  published  as  bulletins. 

The  present  work  forms  No.  88  of  the  Bulletin  series. 

RICHARD  RATHBUN, 
Assistant  Secretary,  Smithsonian  Institution, 

In  charge  of  the  United  States  National  Museum. 

WASHINGTON,  D.  C.,  January  27,  1915. 

3 


M650670 


TABLE  OF  CONTENTS. 


Page. 

Preface 9 

Terminology  as  applied  to  the  skeleton  of  Paleozoic  Asteroidea 13 

Finding  list  of  Paleozoic  Stelleroidea 18 

Remarks  on  the  development  of  Paleozoic  Stelleroidea 27 

Geological 27 

Distribution 27 

Preservation  and  occurrence 28 

Asterid  evolution 30 

General  observations 30 

The  most  primitive  fossil  starfish 31 

Origin  of  the  wriggling  type  of  starfish 32 

The  asterid  radicle 34 

Ontogeny 36 

Regeneration 37 

Number  and  character  of  rays 38 

Development  of  the  parts 39 

Anus 39 

Madreporite 39 

Spinosity 41 

Ambulacralia 41 

Adambulacralia 43 

Inframarginalia 43 

Supramarginalia 45 

Radialia 46 

Accessory  plates 47 

Ocular  plates -^, 48 

Centro-dorsal 48 

Primary  disk-plates 49 

Axillary  ossicles 49 

Interbrachial  areas 50 

Classification 51 

Catalogue  of  Paleozoic  Stelleroidea 51 

Description  of  genera  and  species 51 

Class  Stelleroidea 51 

Subclass  Asteroidea 51 

Phanerozonia 51 

Family  Hudsonasteridae 53 

Hudsonaster 53 

Siluraster 65 

Family  Palseasteridse 66 

Palseaster , 67 

Australaster 72 

5 


6  TABLE    OF    CONTENTS. 

Description  of  genera  and  species — Continued. 
Class  Stelleroidea — Continued. 

Subclass  Asteroidea — Continued. 

Phanerozonia — Continued.  page. 

Family  Promopalaeasteridae 73 

Subfamily  Mesopalaeasterinae 74 

Mesopalseaster 74 

Spaniaster 95 

Miomaster 96 

Devonaster 97 

Subfamily  Promopalasasterinse 102 

Promopalasaster 102 

Subfamily  Anorthasterinae 125 

Anorthaster 125 

Family  Xenasteridae 128 

Xenaster 129 

Agalmaster 131 

Rhenaster 133 

Eifelaster 133 

Trimeraster 134 

Family  Neopalaeasteridse 134 

Neopalseaster 134 

Family  Palasterinidae 138 

Petraster 138 

Lindstromaster 148 

Palasterina 150 

Uranaster 154 

Palseostella 155 

Pseudopalasterina 156 

Family  Lepidasteridae 157 

Lepidaster 158 

Helianthaster 159 

Lepidasterella 160 

Family  unknown 161 

Astropecten 161 

Ataxaster 161 

CryjDtozonia .- 162 

r~Family  Stenasteridae 163 

/             Stenaster 163 

Tetraster 167 

Family  Monasteridaa 170 

Monaster 170 

Family  Urasterellidee 172 

Urasterella 173 

Family  Calliasterellidaa 190 

Calliasterella 190 

Family  Compsasteridse 191 

JaeJcelaster 192 

Compsaster 192 

Family  Schuchertiidae 194 

Schuchertia 195 

Family  Palasteriscidae 199 

Palasteriscus 200 

Echinasterella...                                               200 


TABLE   OF   CONTENTS.  7 

Description  of  genera  and  species— Continued. 
Class  Stelleroidea — Continued. 

Subclass  Asteroidae — Continued. 
Cry  ptozonia — Continued . 

Family  Palasteriscidae — Continued.  Page. 

Loriolaster 201 

Cheiropteraster 202 

Family  Schoanasteridae .  202 

Schcenaster 202 

Family  Palseosolasteridae 207 

Palxosolaster 209 

Echinasterias 211 

Echinodiscaster 211 

Echinostella 212 

Medusaster 212 

Subclass  Auluroidea 213 

Order  Lysophiurae 215 

Family  Protasteridae 215 

^fseniaster 216 

[_  Eophiura. . 222 

Bohemura 223 

L-Palseum 223 

Protester 224 

Akpidaster 228 

Gregoriura 233 

Bunderibachia 234 

Palxophiomyxa 234 

Family  Palaeophiuridae 235 

Palseophiura 235 

Sturtzura 236 

f-JSygasterella 237 

;    Ptilonaster 239 

Family  Encrinasteridse 241 

Encrinaster 241 

Order  Streptophiurae „. 246 

Family  Ophiurinidae 246 

Ophiurina „ 246 

Tremataster 247 

Family  Lapworthuridae 248 

Squamaster 249 

^Lapworthura 250 

r  Sturtzaster 252 

_  Bdellacoma 254 

THhopalocoma 254 

Hallaster 254 

Sympterura 256 

Furcaster 261 

Palastropecten 261 

Family  Eoluidiidae 262 

Eoluidia 262 

Eospondylus 263 

Miospondylus 263 

Family  Aganasteridae 263 

Aganaster 263 

Family  Cholasteridae 265 

Cholaster. . .  265 


8  TABLE    OF    CONTENTS. 

Description  of  genera  and  species — Continued. 

Class  Stelleroidea — Continued.  page. 

Subclass  Ophiuroidea 267 

Family  Onychasteridee 268 

Onychaster 268 

Forms  whose  relationships  are  unknown 274 

Cribellites  carbonarius 274 

Order  Ophiocistia , 275 

Family  Eucladiidse 276 

Eucladia 276 

Euthemon 279 

Bibliography 281 

Explanation  of  plates 289 

Index..  303 


REVISION  OF  PALEOZOIC  STELLEROIDEA  WITH 
SPECIAL  REFERENCE  TO  NORTH  AMERICAN 
ASTEROIDEA 


By  CHARLES  SCHUCHEET 

Professor  of  Paleontology,  Yale  University,  New  Haven. 


PREFACE 

This  memoir  had  its  inception  in  1896,  and  came  about  through 
the  force  of  circumstances.  The  writer,  at  that  tune  assistant  curator 
in  the  United  States  National  Museum,  was  made  aware  of  the  desire 
of  Mr.  I.  H.  Harris,  of  Waynesville,  Ohio,  to  present  to  that  institu- 
tion his  extensive  collection  of  Ordovicic  fossils.  He  had  long  known 
Mr.  Harris,  having  met  him  as  a  young  man,  about  the  year  1876, 
at  which  time  the  Harris  collection  was  already  widely  known,  not 
only  for  its  quantity,  but  more  especially  for  its  many  choice  speci- 
mens of  the  rarer  species  of  starfishes,  crinids,  and  trilobites.  Twenty 
years  later  came  Mr.  Harris's  desire  to  present  to  the  National 
Museum  the  collection  upon  which  he  had  been  at  work  for  fifty 
years.  This  gift  brought  to  the  National  Museum  not  less  than  40 
asterids,  35  (31  on  one  slab)  ophiurids  from  the  Cincinnatic  strata 
(the  great  majority  from  the  Waynesville  formation),  besides  an 
asterid  and  12  specimens  of  Ony chaster  flexilis  from  the  Keokuk 
formation  at  Crawfordsville,  Indiana.  Some  years  later  the  National 
Museum  acquired  the  very  valuable  E.  O.  Ulrich  collection,  in  which 
there  were  also  many  good  starfishes.  Accordingly,  it  is  safe  to  state 
that  in  no  other  museum  are  there  so  many  Ordovicic  asterids,  in  so 
great  a  variety  and  in  such  excellent  preservation. 

The  material  of  the  Harris  collection  seemed  to  show  that  its  com- 
plete study  would  not  only  reveal  much  new  knowledge,  but  give  an 
insight  as  well  into  the  probable  evolution  of  the  Paleozoic  starfishes. 
When  these  facts  were  made  known  to  the  then  director  of  the  National 
Museum,  Dr.  G.  Brown  Goode,  he  asked  the  writer  to  invite  Mr.  Harris 
to  join  him  in  a  work  on  the  Ordovicic  starfishes.  This  was  done  and 
Mr.  Harris  was  greatly  pleased  to  undertake  the  joint  authorship. 
He  did  all  he  could  to  further  the  work,  but  it  went  very  slowly, 
because  the  present  writer  was  so  much  occupied  with  curatorial 
work  as  well  as  the  arranging  of  museum  exhibits  for  the  expositions 
in  which  the  United  States  Government  participated  and  which  came 

9 


10  BULLETIN   88,  UNITED   STATES  NATIONAL   MUSEUM. 

nearly  every  year.  Unfortunately,  Mr.  Harris  died  on  October  17, 
1897,  when  the  work  was  still  in  the  first  stages. 

At  odd  times  during  subsequent  years  the  writer  kept  up  his  studies 
and  in  the  spring  of  1904  the  work  on  the  Asteroidea  was  practically 
completed.  Then  came  his  appointment  to  the  chair  of  paleontology 
at  Yale  University.  Here  new  duties  and  new  lines  of  thought  kept 
him  away  from  the  study  of  the  Paleozoic  ophiurids  which  had  been 
planned,  but  the  hope  was  strong  that  somehow  the  time  would  be 
found  to  complete  the  work.  However,  this  hope  has  not  materialised, 
others  have  gone  to  work  on  the  starfishes,  and  one  genus  and  general- 
ization after  another  has  slipped  away.  Therefore  it  was  thought 
best  to  revise  what  had  been  done,  bringing  the  asterids  up  to  date. 
In  regard  to  the  ophiurids,  it  was  found  impossible  to  restudy  the 
specimens,  but  as  the  writer  had  kept  abreast  of  the  literature,  this 
was  put  into  order  and  is  here  presented,  in  the  hope  that  subsequent 
workers  will  find  it  useful  in  enabling  them  to  find  the  references  on 
any  species  and  the  taxonomic  status  of  any  form. 

A  study  of  the  specimens  in  the  Harris  collection  made  it  plain 
that  no  satisfactory  taxonomic  and  systematic  results  would  follow 
unless  the  undertaking  also  embraced  many  other  Paleozoic  forms, 
of  Europe  as  well  as  of  America.  Species  and  genera  had  been  pro- 
posed in  a  very  loose  manner;  in  fact,  most  of  the  Paleozoic  litera- 
ture on  asterids  and  ophiurids  up  to  the  tune  this  work  began  had 
no  other  value  than  to  force  the  reviser  under  the  rules  of  nomencla- 
ture to  recognize  the  names  proposed.  The  International  Rules  of 
Zoological  Nomenclature  have  here  been  strictly  followed.  Under 
these  circumstances,  all  of  the  type-specimens  had  to  be  seen,  and  most 
of  them  have  been  accessible.  In  this  way  the  work  finally  came  to 
be  extended  to  all  Paleozoic  Stelleroidea.  To  make  it  plain  how  little 
the  American  Paleozoic  starfishes  were  known  in  1889,  it  will  suffice 
to  give  one  example:  Miller  in  his  North  American  Geology  and 
Palaeontology  lists  23  species  under  Palseaster'j  in  the  present  work 
there  is  but  a  single  form  of  this  genus,  the  genotype,  P.  niagarensis, 
the  remainder  having  been  distributed  among  seven  genera,  all  new 
and  proposed  in  the  past  few  years  or  at  this  tune.  As  a  result,  every 
paleontologist  will  be  obliged  to  disregard  what  he  has  learned  re- 
garding American  Paleozoic  starfishes  and  start  anew.  To  facilitate 
this,  a  list  has  been  prepared  and  is  here  presented  of  all  the  names 
so  far  given  to  Paleozoic  asterids  and  ophiurids,  with  cross  references 
to  the  names  adopted  in  this  work. 

Now  that  this  study  is  finished,  at  least  for  the  present,  it  is  plain 
to  the  author  that  his  species  and  genera  are  also  in  some  cases  too 
comprehensive.  The  future  student  will  restudy  the  specimens  along 
with  the  new  material  and  go  more  deeply  into  the  detailed  structure 
of  the  parts.  He  who  attempts  this,  along  with  painstaking  recon- 


EEVISION   OF   PALEOZOIC   STELLEROIDEA.  11 

struction  of  the  skeleton  as  it  was  in  life,  will  learn  where  to  separate 
and  what  to  reject. 

During  the  past  10  years,  Schondorf  has  revised  most  of  the  German 
asterids  and  has  studied  deeply  into  the  structure  of  the  ophiurids. 
His  work  is  very  detailed  and  the  best  extant  on  the  Paleozoic  forms. 
Every  student  of  Stelleroidea  intending  to  do  thorough  work  will 
have  to  examine  his  results.  In  classification  he  has  laid  the  founda- 
tion, and  has  shown  that  some  asterids  are  not  Asteroidea  at  all,  but 
that  they  and  the  bulk  of  the  so-called  ophiurids  of  the  Paleozoic  must, 
because  of  their  peculiar  structure,  ambulacral  and  otherwise,  be 
referred  to  another  class,  the  Auluroidea. 

In  regard  to  the  evolution  of  the  Asteroidea,  the  writer  hoped 
to  find  the  time  to  present  his  views  concerning  it  in  detail  in  this 
memoir,  but  that  also  is  not  possible.  However,  the  main  lines 
and  often  the  generic  directions  of  organic  change  are  stated  and 
will  be  found  either  in  the  introductory  pages  or  scattered  through- 
out the  work,  generally  in  the  remarks  under  the  generic  discussions. 
These  results  in  connection  with  the  work  of  Schondorf,  it  is  thought, 
ought  soon  to  place  the  Paleozoic  Stelleroidea  in  such  order  that 
a  final  classification,  based  on  ontogeny,  chronogenesis,  and  phyl- 
ogeny,  and  embracing  not  only  the  Paleozoic  forms  but  those  of 
Mesozoic,  Cenozoic,  and  Recent  time  as  well,  can  be  made. 

Many  museums  and  individual  paleontologists  have  loaned  the 
writer  the  specimens  in  their  collections  or  in  their  keeping,  and  he 
wishes  here  to  thank  them,  one  and  all,  for  these  loans.  The  greatest 
bulk  of  the  material  studied  is  of  course  in  the  United  States  National 
Museum  in  the  Harris  and  Ulrich  collections;  a  number  of  Trenton 
specimens  and  some  from  the  English  Siluric  have  also  been  given 
to  the  National  Museum  by  Mr.  Walter  R.  Billings,  of  Ottawa. 
Since  the  writer  has  been  in  New  Haven,  Dr.  R.  S.  Bassler,  of  the 
National  Museum,  has  often  kindly  helped  him  to  further  his  studies, 
and  during  the  past  year  has  made  a  large  number  of  photographs 
of  the  specimens  under  his '  charge.  The  many  Mississippic  speci- 
mens in  the  Frank  Springer  collection  have  not  been  studied. 

The  author  is  greatly  indebted  to  Dr.  F.  A.  Bather,  of  the  British 
Museum  (Natural  History),  for  a  large  number  of  gutta-percha  and 
wax  squeezes  made  by  him  of  certain  species  in  that  great  museum. 
These  casts,  which  are  all  in  the  United  States  National  Museum, 
have  enabled  the  writer  to  understand  several  genera  that  otherwise 
he  could  not  have  worked  out.  He  is  also  indebted  to  him  for  many 
bibliographic  corrections  and  suggestions. 

The  second  largest  American  collection  is  at  Harvard  University, 
in  the  Museum  of  Comparative  Zoology.  Most  of  the  material  is 
in  the  Charles  D.  Walcott,  Charles  B.  Dyer,  and  Charles  Wachsmuth 
collections.  In  the  first-named  collection  there  is  excellent  material 
from  the  Middle  Ordovicic;  the  second  has  many  fine  specimens 


12  BULLETIN   88,  UNITED   STATES  NATIONAL  MUSEUM. 

from  the  Cincinnatic  formations;  while  the  Wachsmuth  material  has 
species  from  the  Mississippic.  To  all  of  this  material  the  author 
has  had  access  through  the  kindness  of  Director  Samuel  Henshaw 
and  Profs.  R.  T.  Jackson  and  P.  E.  Raymond. 

At  the  University  of  Chicago  there  is  a  great  deal  of  excellent 
material  in  the  W.  F.  E.  Gurley,  Charles  Faber,  and  U.  P.  James 
collections,  to  which  Weller  has  added  other  specimens.  All  of  this 
material  has  been  studied  through  the  courtesy  of  Prof.  Stuart 
Weller.  Most  of  it  is  from  the  Cincinnatic  formations. 

All  of  the  specimens  described  by  E.  Billings  and  now  in  the  Vic- 
toria Memorial  Museum  in  Ottawa,  Canada,  have  been  seen  at  one 
tune  or  another.  In  this  matter  the  writer  was  much  aided  by  the 
late  Dr.  J.  F.  Whiteaves  and  more  recently  by  Drs.  P.  E,  Raymond 
and  E.  M.  Kindle,  to  the  latter  of  whom  thanks  are  also  due  for 
several  photographs  reproduced  in  this  memoir.  Most  of  the  speci- 
mens are  from  the  Ordovicic. 

In  the  University  of  Toronto  there  is  much  material  from  the 
Ordovicic  and  Siluric  in  the  Sir  Edmund  Walker  collection,  and  there 
may  be  studied  a  great  many  specimens  of  Stenaster  salteri.  All  of 
this  has  been  seen  through  the  great  liberality  of  Prof.  William  A. 
Parks. 

The  genotype  of  Pakeaster,  from  the  museum  of  Cornell  University, 
was  loaned  to  the  author  at  different  times  by  Prof.  H.  S.  Williams. 
It  is  one  of  the  best  preserved  of  Paleozoic  specimens  and  has  become 
very  valuable  because  of  the  continual  discussion  that  centers 
around  the  species,  P.  niagarensis. 

To  all  the  specimens  in  the  Peabody  Museum  of  Yale  University 
access  was  had  through  the  kindness  of  the  late  Prof.  Charles  E. 
Beecher.  Among  them  is  the  unique  branching  form,  Eucladia 
beecfieri. 

Photographs  have  been  made  for  this  memoir  by  Dr.  John  M. 
Clarke  of  specimens  in  the  New  York  State  Museum,  and  by  Prof. 
George  H.  Hudson,  of  Plattsburg,  New  York,  of  other  material. 
Prof.  Arthur  M.  Miller  loaned  two  specimens  that  he  collected  and 
deposited  in  the  State  University,  Lexington,  Kentucky.  Prof.  George 
W.  Harper,  of  Cincinnati,  loaned  a  specimen  of  Palseaster  darkana 
( =  Hudsonaster  incomptus) . 

Nearly  all  the  original  drawings  were  traced  from  the  specimens 
by  aid  of  the  camera  lucida.  These  outlines  were  then  inked  and 
shaded  by  the  late  Dr.  J.  C.  McConnell,  a  draftsman  and  artist  of 
the  first  rank. 

To  Miss  Clara  Mae  LeVene  the  writer  is  especially  thankful  for 
the  great  interest  she  has  taken  hi  getting  the  manuscript  into  order 
for  the  printer,  keeping  the  bibliography  up  to  date  and  correctly 
citing  it,  and  for  the  careful  reading  of  the  proof. 


REVISION   OF  PALEOZOIC   STELLEBOIDEA.  13 

TERMINOLOGY  AS  APPLIED  TO  THE   SKELETON  OF  PALEOZOIC 

ASTEROIDEA.1 

Abactinal. 

See  Body-wall.  The  integumentary  skeleton  opposite  to  that  having  the  ambu- 
lacral  grooves,  or  that  of  the  upper  or  dorsal  side  of  the  animal.  Also  known 
as  the  aboral  surface.  See  Actinal. 

Aboral. 

See  Abactinal. 

Accessory  plates. 

This  term  refers  to  the  abactinal  longitudinal  columns,  or  transverse  rows,  of  small 
plates  between  the  radials  and  supramarginals  (=radial  accessory  plates  or  dorso- 
laterals),  or  between  the  inframarginals  and  supramarginals  (=ambital  plates  or 
intermarginals),  or  where  there  are  no  radials,  to  all  the  ossicles  between  the  two 
supramarginal  columns.  There  may  also  be  accessory  actinal  plates  which  are 
termed  accessory  interbrachials,  accessory  actinals,  or  inter actinals.  The  accessory 
plates  form  the  secondary  skeleton  and  are  inserted  between  the  columns  of 
the  primary  skeleton.  It  is  in  the  secondary  skeleton  that  much  of  the 
specific  and  generic  evolution  takes  place.  See  Interbrachial. 

Actinal. 

See  Body-wall.  The  integumentary  skeleton  with  the  ambulacral  grooves,  or 
that  of  the  under  or  ventral  side  of  the  animal.  Also  known  as  the  oral  surface. 

Adambulacrals. 

The  single  columns  of  prominent  plates  adj  oining  the  ambulacrals .  There  are  never 
more  than  two  of  these  columns  in  a  ray,  one  on  each  outer  side  of  the  depressed 
ambulacrals.  They  are  generally  large  and  thick  and  bear  the  larger,  or  adam- 
bulacral,  spines .  These  spines  may  be  inwardly  directed  and  serve  as  a  protection 
for  the  tube-feet.  The  oral  armature  in  Paleozoic  species  usually  consists  of  five 
pairs  of  modified  adambulacrals,  each  pair  being  the  oral  projection  of  two  united 
columns  of  adjoining  rays.  They  are  also  called  Adambulacralia.  Also  see  Inter- 
brachial. 

Ambital. 

The  abactinal  space  between  the  infra-  and  supramarginal  columns,  occupied  by 
accessory  plates.  These  are  best  developed  in  the  axillary  disk  areas  (disk  ambi- 
tals),  while  those  of  the  rays  are  referred  to  as  ray  ambitals.  They  are  also 
known  as  intermarginals. 

Ambulacral. 

Ambulacral  grooves  (five  or  more),  plates,  or  ossicles  are  situated  actinally  and  per- 
radially  along  the  center  of  the  rays  and  disk.  They  are  also  called  ambula- 
cralia.  The  ambulacral  columns  are  in  pairs,  the  interlocking  movable  plates 
of  adjoining  columns  may  be  alternate  or  opposite  (always  so  in  recent  forms), 
and  the  plates  of  a  column  may  be  superposed  like  the  tiles  on  a  roof.  The 
podial  openings  through  which  the  fleshy  tube-feet  protrude  are  situated  be- 
tween the  sutures  of  adjoining  plates.  In  early  forms  there  are  but  two  columns 
of  podial  openings  in  each  ray,  one  on  each  side  of  the  axial  line,  but  in  later 
forms  there  may  be  as  many  as  eight  columns.  The  ambulacral  grooves  may 
be  tapering  or  petaloid. 

Anal  opening. 

The  only  Paleozoic  form  in  which  an  anal  opening  may  exist  visually  is  Hudson- 
aster.  Here  it  is  on  the  disk  between  the  central  plate  and  the  madreporite. 
The  anal  pore  is  nearly  always  obscured  in  fossil  starfishes,  and  is  absent  in  some 
recent  species. 

1  Also  in  the  main  applicable  to  the  Auluroidea  and  somewhat  to  the  Ophiuroidea. 


14  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

Arcs. 

See  Axil. 
Axil. 

The  angle  formed  by  the  junction  of  the  rays.  Also  known  as  arcs.  In  primitive 
forms  each  axil  is  occupied  by  a  single  plate,  the  axillary  inframarginal.  In 
others  this  plate  is  crowded  orally  and  its  place  occupied  by  two  prominent 
proximal  inframarginals.  In  forms  with  large  disks  having  well-developed 
marginals  these  are  termed  disk  marginals.  Also  see  Ambital  and  Interbrachial. 
Bivium. 

The  two  rays  of  a  starfish  that  inclose  between  them  the  madreporite.  When 
oriented  toward  the  student,  the  ray  on  the  left  is  numbered  1  and  the  other  on 
the  right  is  numbered  5.  A  line  drawn  through  the  madreporite  and  the  center 
of  the  upward  directed  ray  (ray  3)  divides  the  animal  into  symmetrical  halves 
(=left  and  right  sides).  The  upper  left-hand  ray  is  numbered  2  and  the  one 
opposite  is  4.  Rays  2,  3,  and  4  form  the  trimum. 
Body-wall. 

The  outer  surface  of  both  disk  and  rays,  made  up  of  movable  calcareous  plates 
which  are  either  closely  adjoining  or  form  a  more  or  less  loose  network  of  ossicles. 
These  are  held  together  in  the  living  animal  by  connective  tissue  and  muscular 
fibers,  which  after  death  soon  decompose,  freeing  the  plates.  It  is  for  this  reason 
that  fossil  starfishes  are  so  rarely  found  entire.  Imbedded  in  the  body-wall 
everywhere  are  blunt,  short,  calcareous  spines,  arranged  in  a  more  or  less 
definite  order,  and  often  movable  upon  the  underlying  plates. 

Covering  the  whole  surface  of  the  body,  including  the  spines  and  pedicellarise, 
is  a  delicate  membrane  or  skin,  clothed  externally  with  closely  placed  vibratile 
cilia,  which  keep  the  integument  clean.    The  calcareous  skeleton  of  starfishes 
is  therefore  integumentary. 
Csecal  pores. 

The  openings  between  reticular  plates  for  the  protrusion  of  the  respiratory  csecal 
processes.    These  pores  are  either  restricted  to  the  abactinal  area  or  may  be 
distributed  over  the  entire  body.    The  processes  are  also  known  as  papulx. 
Central  disk. 

See  Disk. 
Central  disk  plate. 

A  prominent  plate,  most  conspicuous  in  primitive  forms,  which  often  appears  in 
the  center  of  the  disk.     It  holds  the  same  position  as  the  centro-dorsal  plate  in 
embryonic  crinids  of  the  genus  Antedon.    Also  called  the  abactinal-central  plate 
or  simply  central  plate. 
Centro-dorsal  plate. 

See  Central  disk  plate. 
Disk. 

The  central  portion  of  a  starfish.  In  this  work,  the  term  generally  applies  only  to 
the  abactinal  central  area  formed  either  by  the  union  of  the  rays,  or  by  the  rays 
plus  the  axillary  areas.  The  mouth  is  in  the  center  of  the  disk  on  the  under  or 
actinal  side .  Disk  plates  are  the  small  plates  over  this  area  on  the  abactinal  side . 
Central  disk  plate  refers  to  a  larger  primary  plate  in  the  center  of  the  disk.  There 
may  be  other  large  primary  plates,  but  these  are  more  properly  referred  to  the 
rays.  See  Radial,  Interradial,  Marginal,  and  Ambital. 
Inframarginal. 

See  Marginal  plates. 
Interbrachial. 

The  actinal  and  marginal  areas  between  the  rays .  These  spaces  have  plates  derived 
from  various  regions.  In  primitive  forms,  but  a  single  plate  is  present,  the 
axillary  interbrachial,  derived  by  crowding  orally  the  axillary  inframarginal. 
In  other  genera,  inframarginals  are  crowded  in  pairs  orally  and  form  interbrachial 


REVISION   OF   PALEOZOIC   STELLEBOIDEA.  15 

areas,  the  interbrachial  marginals.  Or  the  adambulacrals  may  enter  into  the 
construction  of  these  areas,  forming  interbrachial  adambulacrals.  When  the  adam- 
bulacrals and  inframarginals  are  separated  by  small  plates,  the  latter  are  called 
accessory  interbrachials;  they  may  extend  almost  to  the  distal  ends  of  the  rays. 

Interradial. 

A  point  half-way  between  the  perradii.  The  interambulacral  areas  are  inter- 
radial  in  position.  See  Perradial. 

Interradial  plates. 

These  abactinal  plates  are  rarely  retained  in  living  mature  starfishes.  In  many 
Paleozoic  genera  they  are  large,  interradial  in  position,  five  in  number,  and 
lie  inside  the  basal  or  proximal  supramarginals  and  between  the  primary  radials. 
They  may  be  homologous  with  the  basals  of  crinids.  They  are  also  known  as 


Madreporite  ormadreporic  plate. 

A  sieve-like  or  spongy  plate,  with  many  irregular  openings  for  the  circulation 
of  sea  water  into  the  so-called  "stone  canal,  "  or  better,  into  the  water- vascular 
system.  It  is  commonly  granular  or  striated,  and  in  Asteroidea  is  abactinal 
on  the  disk,  basally  situated  between  two  rays,  but  in  the  Auluroidea  is  prob- 
ably always  actinal  in  position.  In  recent  multiradiate  forms  there  are  species 
with  more  than  one  madreporite. 

Marginal  plates. 

In  general  the  plates  which  make  up  the  marginal  columns  bounding  the  rays, 
or  disk,  or  the  entire  animal.  They  are  parts  of  the  primary  skeleton.  In  the 
early  Paleozoic  genera  the  inframarginal  and  supramarginal  columns  are  usually 
not  directly  superposed,  making  one  column  of  superposed  halves  as  in  Meso- 
zoic  and  Recent  starfishes,  but  the  former  column  lies  outside  or  laterally  of 
the  latter.  The  inframarginals  are  then  the  true  marginals,  and  form  a  part 
of  both  the  abactinal  and  actinal  sides.  In  the  primitive  arrangement  the 
inframarginals  adjoin  the  adambulacrals,  but  in  derived  forms  with  large  pen- 
tagonal disks  they  are  separated  from  the  latter  by  accessory  interbrachial  plates. 
The  situation  of  the  marginals  is,  however,  not  always  at  the  margin  of  the 
disk  and  rays,  but  they  may  retain  their  primitive  position  beside  the  adam- 
bulacrals; this  is  more  especially  true  in  forms  having  a  well-developed  pen- 
tagonal disk.  These  plates  are  also  referred  to  as  marginalia,  supramarginalia, 
and  inframarginalia. 

In  some  forms  the  supramarginals  are  not  recognizable  as  such,  while  the  infra- 
marginals  are  well-developed;  and  in  others  none  of  the  marginals  are  distinctly 
discernible.  Sometimes  the  plates  of  the  inframarginal  columns  adjoin  one 
another,  while  those  of  the  supramarginal  series  are  separated  by  small  acces- 
sory supramarginal  pieces.  Then  the  inframarginals  may  be  separated  from 
the  supramarginals  by  ambital  ossicles  (see  Ambital) .  A  proximal  supramarginal 
is  the  proximal  plate  of  a  column  and  may  not  be  homologous  with  the  primary 
supramarginal  in  primitive  forms.  Proximal  inframarginal  is  used  in  a  similar 
way  and  refers  to  the  proximal  axillary  plate,  two  of  which  of  adjoining  col- 
umns occupy  an  axil  or  lie  on  either  side  of  the  axillary  marginal.  The  latter 
in  primitive  forms  alone  occupies  the  angle  between  the  rays.  The  marginals 
in  large  disks  without  angles  may  be  termed  disk  infra-  and  supramarginals. 
The  large  disk  of  some  species  is  formed  by  the  oral  crowding  of  pairs  of 
proximal  inframarginals,  the  interbrachial  marginals. 

Measurements. 

The  size  of  starfishes  is  usually  given  in  millimeters  along  the  greater  and  lesser 
radii,  that  is,  from  the  center  of  the  mouth  or  disk  to  the  tips  of  the  rays.    The 
symbol  for  this  line  is  R.    The  smaller  radius  is  from  the  center  of  the  animal 
to  the  center  of  the  interradii;  the  symbol  is  r. 
50601°— Bull.  88—15 2 


16  BULLETIN   88,  UNITED   STATES   NATIONAL  MUSEUM. 

Mouth  angle  plate. 

See  Oral  armature. 
Ocular  plate. 

A  single  large,  grooved  eye-plate  occupying  the  distal  ends  of  rays  and  support- 
ing a  sensory  tentacle  at  the  base  of  which  occurs  the  eye-spot.  They  appear  in 
the  larval  stage  as  the  primary  radials  and  with  growth  pass  outward,  remain- 
ing at  the  tip  of  the  rays  as  the  oculars.  They  are  also  known  as  terminals. 
These  large  plates  are  not  present  .as  such  in  early  Paleozoic  genera,  and  are 
unknown  before  the  Carboniferous. 
Oral. 

See  Actinal. 
Oral  angles. 

The  interradial  actinal  areas  around  the  mouth. 
Oral  armature. 

The  pairs  of  plates,  usually  five  in  number,  composing  the  apices  around  the 
central  actinal  opening  or  mouth.  In  most  Paleozoic  forms  the  armature 
consists  of  the  proximal  modified  adambulacral  plates.  These  pieces  are  also 
known  as  Mouth  angle  plates. 

In  some  Paleozoic  forms  (Hudsonaster)  there  lies  in  front  of  each  pair  of  mouth 
angle  plates  a  single  plate;  this  is  known  as  the  Torus. 

Gregory  (1900,  p.  241)  writes  that  "the  Oral  Skeleton  (or  actinostomial  ring) 
consists  of  a  solid  calcareous  ring  around  the  mouth.  It  is  composed  of  thirty 
plates  in  a  quinqueradiate  starfish,  there  being  always  six  times  as  many  plates 
as  there  are  rays.  Each  segment  of  the  oral  skeleton  consists  of  two  pairs  of 
ambulacral,  and  of  one  pair  of  adambulacral  ossicles.  In  Asterias  [a  cryp- 
tozonian]  the  ambulacral  plates  are  more  prominent  than  the  adambulacrals, 
and  project  into  the  oral  cavity." 

When  the  ambulacral  elements  are  the  more  prominent,  the  oral  skeleton  is  said 
to  be  of  the  ambulacral  type.  This  is  only  present  in  cryptozonians.  When 
the  adambulacral  ossicles  are  the  most  prominent,  the  oral  skeleton  is  of  the 
adambulacral  type.  This  latter  construction  is  the  more  primitive  and  occurs 
in  all  the  Phanerozonia,  but  is  also  present  in  some  of  the  cryptozonians. 
Ossicles. 

See  Plates. 
Papulae. 

In  living  Asterias,  a  cryptozonian,  from  between  the  spicular  plates  there  rise 
from  all  parts  of  the  external  surface  short  and  small  integumentary  protuber- 
ances that  are  used  for  respiration.  In  the  more  heavily  plated  Phanerozo- 
nia they  are  limited  to  the  abactinal  surface  enclosed  between  the  supramar- 
ginal  plates.  It  is  probable  that  papulae  were  present  in  all  Paleozoic  forms 
having  rounded  or  spicular  ossicles,  issuing  in  the  open  spaces  between  the 
plates.  They  probably  were  absent  in  the  earliest  closely  plated  starfishes, 
such  as  Hudsonaster.  See  Csecal  pores. 
Paxillse. 

Minute  calcareous  processes  arranged  around  large  spines.  None  are  known 
in  Paleozoic  genera. 

"Another  type  of  spines  occurs  as  part  of  the  structures  known  as  'paxillse.' 
Each  paxilla  consists  of  a  thick  plate  supporting  a  number  of  short,  calcareous 
pillars,  the  summit  of  each  of  which  is  covered  by  a  group  of  small  spines. 
In  some  Phanerozonia  *  *  *  the  paxillse  occupy  almost  the  whole  abactinal 
surface  of  the  Asteroid"  (Gregory  1900,  p.  247). 
Pedicellarids. 

Pincer  or  scissors-like  calcareous  appendages,  attached  to  the  spines,  the  plates, 
or  the  skin,  which  keep  the  body-wall  clean  of  parasites.  None  have  as  yet 


KEVISION   OF  PALEOZOIC   STELLEROIDEA.  17 

been  detected  with  certainty  in  Paleozoic  genera.  In  the  primitive  Recent 
forms  they  are  also  absent,  the  integument  being  protected  by  an  abundance 
of  closely  set  spines. 

"The  Pedicellarise  of  Asteroids  are  of  four  main  types.  The  simplest  form  con- 
sists of  a  row  of  pairs  of  small,  sessile,  opposable  spines;  these  are  the  'pseudo- 
pedicellariae.*  The  members  of  the  second  set  are  '  sessile.'  The  next  advance 
is  the  development  of  a  stalk;  of  these  pedunculate  pedicellariae  there  are  two 
varieties:  (1)  the  'forficiform,'  in  which  the  two  hooks  are  attached  to  the  near- 
est end  of  the  basal  plate  nearest  to  them;  (2)  the  'forcipiform,'  in  which  the 
two  hooks  cross  one  another  and  are  attached  to  the  end  of  the  basal  plate  far- 
thest from  them  "  (Gregory  1900,  p.  247;  also  see  Verrill  1914,  pp.  25-34). 
Perradial. 

The  area  along  the  center  of  the  rays.    The  ambulacra  are  perradial  in  position. 

See  Interradial. 
Plates. 

Some  writers  restrict  the  term  plates  to  the  five  primary  radials,  five  interradials, 
and  the  central  disk  piece,  and  refer  to  all  the  other  calcareous  parts  as  ossicles. 
The  word  plates  is  here  used  in  the  widest  sense,  and  as  interchangeable  with 
ossicles.  For  the  sake  of  brevity  the  plates  will  be  often  referred  to  as  margi- 
nalia, radialia,  etc. 
Podial  openings. 

The  rounded  openings  between  the  ambulacral  plates  for  the  protrusion  of  the 

locomotor  organs,  the  podia  or  water- tube-feet.    See  also  Ambulacral. 
Primary  radial. 
See  Radial. 
Primary  skeleton. 

The  skeleton  of  a  starfish  is  made  up  of  primary  and  secondary  ossicles.  The 
primary  skeleton  consists  of  the  longest  inherited  and  the  first  appearing  plates 
in  the  young,  as  the  ambulacral,  adambulacral,  marginal  and  radial  columns, 
plus  the  primary  pieces  of  the  disk.  All  the  other  ossicles  inserted  between 
these  are  of  the  secondary  skeleton. 
Radial 

Refers  only  to  the  prominent  abactinal  primary  plates  holding  a  radial  position. 
Where  present,  they  form  columns  of  continuous  reticular  or  separated  radialia, 
situated  along  the  radial  center  of  the  rays.  Proximal  radials  are  those  on  or 
near  the  disk  and  should  not  be  confounded  with  the  primary  radials,  the 
probable  homologues  of  the  radials  in  crinids.  These  plates  are  also  known  as 
median  dorsals,  dorsals  or  carinals;  also  as  radialia. 
Rays. 

The  radial  "arms  "  of  starfishes.    These  are  hollow  and  contain  the  digestive, 
reproductive,  and  water-vascular  systems  and  other  organs.    The  rays  merge 
gradually  and  without  sharp  demarcation  into  the  central  disk. 
Respiratory  pores. 

See  Csecal  pores. 
Secondary  skeleton. 

See  Primary  skeleton  and  Accessory  plates. 
Spines. 

See  PaxillsR  and  Pedicellarids. 
Supramarginal. 

See  Marginal  plates. 
Terminals. 

See  Ocular  plate. 


18  BULLETIN   88,   UNITED   STATES   NATIONAL  MUSEUM. 

Torus. 

See  Oral  armature. 
Trimum. 

See  Bivium. 
Vertebral  ossicles. 

In  the  Ophiuroidea  each,  pair  of  adjoining  ambulacralia  is  united  into  a  single 
plate,  the  vertebra  of  the  arms.  As  the  arms  are  very  flexible,  these  ossicles 
articulate  upon  one  another  as  do  the  bones  in  the  vertebral  column  of  verte- 
brates. 

FINDING  LIST  OF  PALEOZOIC  STELLEROIDEA. 

Page. 

Acroura  (Ophiura)  schlotheimii  Minister.     Known  to  the  writer  only  from  the  list 
in  Woodward,  Geol.  Mag.,  dec.  2,  vol.  1, 1874,  p.  7.     Siluric. 

Agalmaster  Schondorf 131 

A.  grandis  Schondorf 132 

A.  intermedius  Schondorf 133 

A.  miellensis  Schondorf 132 

Aganaster  Miller  and  Gurley 263 

A.  gregarius  (Meek  and  Worthen) 264 

A.  (?)  ep.  Miller  and  Gurley =Lapworthura  (f )  ep .• 251 

Alepidaster  Meek 228 

A.  flexuosus  (Miller  and  Dyer) 231 

A.  granuliferus  (Meek) 230 

A.  gregarius  Meek= Aganaster  gregarius 264 

A.  miamiensis  (Miller) 233 

A.  f,  new  species -.- 230 

Anorthaster,  new  genus 125 

A.  miamiensis  (Miller) 127 

Archaeasterias  'M.\JlleY=Xenaster 129 

?  Argaster  "0.2^1— Mesopalxaster 74 

A.  antiqua  Gregory = Mesopalxaster  (?)  antiquus 86 

Aspidosoma  Goldi\i88=Encrinaster 241 

A.  arnoldi  Goldf\i8s=Encrinaster  arnoldi 243 

A.  eifelense  SchondoTi=Encrinaster  eifelensis 244 

A.  goldfussi  Sch6ndori=Encrinaster  goldfussi 243 

A.  grayss.  Spencer=Encrinaster  (?)  grayse 245 

A.  petaloides  SimonovitBch=Encrinaster  petaloides 243 

A.  petaloides  goslariensis  Halfar=J!£?icrmas£er  petaloides  goslariensis 243 

A.f  pontis  Cla,Tke=Encrinaster  pontis 244 

A.  roemeri  Schdndori=Encrinaster  roemeri 244 

A.  schmidti  Sch6ndoTi=Encrinaster  schmidti 244 

A.  tischbeinianum Roemer=J£ncrwaster  tischbeinianus 244 

Asterias  Graham,  Anthony,  and  3ameB=Petraster  (?)  americanus 146 

A.  acuminatus  Simonovitsch= Mesopalseaster  (?)  acuminatus 93 

A.  anthonii  Dana=Pefr aster  (?)  americanus 146 

A.  antiqua  ILi8mger=Lindstrdmaster  antiquus 149 

A.  antiqua  Troost=  Mesopalseaster  (?)  antiquus 86 

A.  antiquata  Ijocke=Promopalseaster  spedosus 109 

A.  asperula  Roemer=  Urasterella  asperula 188 

A.  asperula  Roemer  (pait)=Eoluidia  decheni 262 

A.  constellata  Thorent=  Urasterella  (?)  constellata .' 187 

A.  matutina  'BsX\.=Hudsonaster  matutinus '. 57 

A.  montanus  Stschurowsky=  Urasterella  montana 189 

A.  primseva  Salter  and  Soweiby=Stenaster  (?)  obtusus 167 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  19 

Page. 

Asterias  primordialis  Anon.=Promopalseaster,  sp.  undet 108 

A.  (Archseasterias)  rhenana  M.ulleT=Xenaster  (?)  rhenanus 131 

A.  spinosissima  Roemer.    An  unsolved  starfish  from  the  Lower  Devonic  of 
Bundenbach,  Germany.     See  Roemer,  Palaeontographica,  vol.  9, 1863,  p.  147, 
pi.  29,  fig.  4;  and  Schondorf,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden, 
vol.  62,  1909,  p.  33. 
A.  sp.  undet.  Hall  1847—Ccelaster  tenuiradiatus . 

Asteriscus  antiquus  Pictet=Lindstromaster  antiquus 149 

Astropecten  Link . .  161 

A.  (?)  schluteri  Stiirtz 161 

Ataxaster  Jaekel 161 

A.  pygmxus  Jaekel 161 

Australaster,  new  genus 72 

A.  giganteus  (Etheridge) -  -  73 

A.  (?)  stutchburii  (Etheridge) 73 

Bdellacoma  Salter 254 

B.  vermiformis  Salter 254 

Bohemura  Jaekel 223 

B.  jahni  Jaekel 223 

Bundenbachia  Stiirtz 234 

B.  beneckei  Stiirtz 234 

B.  grandis  St\\rtz=Pala£ophiomyxa  grandis 235 

Calliaster  Trautschold=CaZtoere«a 190 

C.  mirus  TT&\itschold=Calliasterella  mira 190 

Calliasterella,  new  name 190 

C.  mira  (Trautschold) 190 

Cheiropteraster  Stiirtz 202 

C.  giganteus  Stiirtz 202 

Cholaster  Worthen  and  Miller 265 

C.  peculiaris  Worthen  and  Miller 266 

Ccelaster  Sandberger=$/>ara'aster 95 

C.  americanus  D'Orbigny=Pe£ras£er  (?)  americanus 146 

C.  latiscutatus  Sandberger=£parmister  latiscutatus 96 

C.  tenuiradiatus  D'Orbigny,  Prodr.  de  Paleont.,  vol.  1, 1849,  p.  22.     Based  on 

an  isolated  madreporite  described  as  Asterias,  sp.  undet.,  Hall,  Pal.  New 
York,  vol.  1,  1847,  p.  18,  pi.  4,  figs,  lla,  116. 

Compsaster  Worthen  and  Miller 192 

C.  formosus  Worthen  and  Miller 193 

C.,  new  species 194 

Cribellites  carbonarius  Tate 274 

Devonaster,  new  genus 97 

D.  chemungensis,  new  species 101 

D.  eucharis  (Hall) 98 

E chinas terella  Stiirtz 200 

E.  ?  darwini  Clarke 200 

E.  sladeni  Stiirtz 200 

Echinasterias  Stiirtz 211 

E.  spinosus  Stiirtz 211 

EchJLnodiscaster  Delage  and  Herouard 211 

E.  multidactylus  (Stiirtz) 211 

Echinodiscites  SchucheTt=Echinodiscaster 211 

Echinodiscus  Stwrtz=Echinodiscaster 211 

E.  multidactylus  St\ulz=Echinodiscaster  multidactylus 211 


20  BULLETIN   88,  UNITED  STATES  NATIONAL  MUSEUM. 

Page. 

Echinostella  Stiirtz 212 

E.  traquairi  Stiirtz 212 

Eifelaster  Schondorf 133 

E.  follmanni  Schondorf 134 

Encrinaster  Haeckel 241 

Encrinaster  Haeckel  (p&rt)=Protaster. . . : 224 

E.  arnoldi  (Goldfuss) 243 

E.  eifelensis  (Schondorf) 244 

E.  goldfussi  (SchSndorf). . r 243 

E.  grayse,  (Spencer) 245 

E.  petaloides  (Simonovitsch) 243 

E.  petaloides  goslariensis  (Halfar) 243 

E.  pontis  (Clarke) 244 

E.  roemeri  (Schondorf) 244 

E.  schmidti  (Schondorf) 244 

E.  tischbeinianus  (Roemer) 244 

Eoactis  Spencer.     See  Urasterella 173 

E.  simplex  Spencer.     See  Urasterella  girvanensis 186 

Eoluidia  Stiirtz 262 

E.  decheni  Stwtz 262 

Eophiura  Jaekel 222 

E.  bohemica,  new  species 222 

Eophiurites  Stiirtz =Eoluidia 262 

E.  decheni  (Stiirtz) =Eoluidia  decheni 262 

Eospondylus  Gregory 263 

E.  primigenius  (Stiirtz) 263 

Etheridgaster  Gregory=  Monaster 170 

E.  clarJcei  Gregory =  Monaster  clarJcei 172 

Eucladia  Woodward 276 

E.  (?)  beecheri,  new  species 278 

E.  johnsoni  Woodward 276 

E.  woodwardi  Sollas 277 

Eugaster  ILal\=EiLgasterella 237 

E.  continnus  Ringueberg=Eugasterella  ( ?)  concinna 239 

E.  logani  H&\\=Eugasterella  logani 238 

Eugasterella,  new  name 237 

E.  ( ?)  concinna  (Ringueberg) 239 

E.  logani  (Hall) 238 

Euryak  annulatum  DeKay.    Apparently  a  lysophiurid.    See  Hall,  Pal.  N.  Y., 

vol.  3,  1861,  p.  134  (nomen  nudum). 

Euthemon  Sollas , 279 

E.  igerna  Sollas 279 

Furcaster  Stiirtz 261 

F.  (?)  daoulasensis  (Davy) 261 

F.  palseozoicus  Stiirtz 261 

Gregoriura  Chapman 233 

G.  spryi  Chapman. . .- 234 

HaUaster  Stiirtz 254 

#./or&m(Hall) 255 

Helianthaster  Clarke  (part)==PaZa20$oZoster 209 

Helianthaster  Roemer 159 

H.  filiciformis  Woodward 160 

H.  gyalum  Clarke =PaZasoso  Zoster  ( ?)  gyalum 210 


REVISION   OF  PALEOZOIC   STELLEKOIDEA.  21 

Page. 

Helianthaster  gyalum  Clarke  (paTty—Lepidasterella  babcocki 160 

H. ,  new  species  Clarke —Lepidasterella  babcocki 160 

H.  rhenanus  Roemer 159 

H.  roemeri  Clarke— PaZasoso  Zoster  roemeri 211 

Hisingeraster  Stiirtz  =Lindstromaster 148 

H.  antiqua  Sturtz=Lindstrdmaster  antiquus 149 

Hudsonaster  Stiirtz 53 

H.  batheri,  new  species 65 

H.  incomptus  (Meek) 61 

H.  matutinus  (Hall) 57 

E.  milleri,  new  species 60 

H.  narrawayi  (Hudson) 59 

H.  rugosus  (Billings) 64 

Jaekelaster  Stiirtz 192 

/.  petaliformis  Stiirtz 192 

Lapworthura  Gregory 250 

L.  cylindrica  Parks=  Tseniaster  cylindricus 220 

L.  miltoni  (Salter) 251 

L.  sollasi  Spencer 251 

L.  (?)sp 251 

Lepidaster  Forbes 158 

L.  grayi  Forbes 158 

Lepidasterella,  new  genus 160 

L.  babcocki,  new  species 160 

Lindstromaster  Gregory 148 

L.  antiquus  (Hisinger) 149 

Loriolaster  Stiirtz 201 

L.  mirabilis  Stiirtz 201 

Medusaster  Stiirtz 212 

M.  rhenanus  Stiirtz 212 

Mesopaleeaster,  new  genus 74 

M.  ( ?}  acuminatus  (Simonovitsch) 93 

M.  (?)  antiquus  (Troost) 86 

M.  bellulus  (Billings) 91 

M.  caractaci  (Gregory) 92 

M.  ( ?)  cataractensis,  new  species 89 

M.  (?)  clarki  (Clarke  and  Swartz) 94 

M .  ( ?)  dubius  (Miller  and  Dyer) 85 

M.finei  (Ulrich) 81 

M.  granti  (Spencer) 89 

M.  intermedius,  new  species 79 

M.  ( ?)  lanceolatus,  new  species 82 

M.  (?)  parviusculus  (Billings) 87 

M.  proavitus,  new  species 83 

M.  sha/eri  (Hall) ; 77 

M.  ( ?)  wilberanus  (Meek  and  Worthen) 84 

Miomaster  Schondorf 96 

M.  drevermanni  Schondorf 96 

Miospondylus  Gregory 263 

M.  rhenanus  (Stiirtz) 263 

Monaster  Etheridge 170 

Monaster  Gregory= Australaster 72 

M.  darkei  (De  Koninck) 172 


22  BULLETIN  88,  UNITED  STATES  NATIONAL  MUSEUM. 

Page. 

Monaster  giganteus  'Ethendge=Australaster  giganteus 73 

M.  stutchburii  JZtheridge=Australaster  stutchburii 73 

Neopalseaster,  new  genus 134 

N.  crawJordsmlUnsis  (Miller) 136 

Onychaster  Meek  and  Worthen 268 

0.  asper  Miller 272 

0.  barrisi  (Hall) 272 

0.  confragosus  Miller 273 

0.  demissus  Miller 274 

0.  flexilis  Meek  and  Worthen 270 

Ophiopege  ~Bohm=Aganaster 263 

Ophiura  obtusa  Eichwald= Pro  taster  (Ophiura)  obtusus. 

0.  (?)  ramosa  Fahrenkohle.    Unknown  to  writer.    See  Bull.  Soc.  Imp.  Nat. 

Moscow,  n.  ser.,  vol.  17,  1844,  p.  208,  pi.  3,  figs.  1-3;  and  Woodward,  Geol. 

Mag.,  dec.  2,  vol.  1,  1874,  p.  7  (listed  only).      Coal  Measures. 

0.  rhenana  Sturtz= Miospondylus  rJienanus 263 

0.  salteri  Salter  and  Sowerby =Protaster  ( ? )  salteri 227 

0.  schlotheimii  Munster= Acroura  (Ophiura)  schloiheimii. 

Ophinrella  Stwrtz=Eospondylus 263 

0.  primigenia  St\irtz=Eospondylus  primigenius 263 

Ophiurina  Stiirtz 246 

0.  lymani  Stiirtz 247 

Palseaster  Hall 67 

Paleeaster  of  authors =Hudsonaster}    Mesopalseaster,    Devonaster,  Promopal- 

seaster,  Anorihaster,    Neopalseaster,    Petraster,  Palasterina,    Monaster,    Uras- 

terella. 

Palseaster  (Monaster)  Etheridge= Monaster 170 

Paleeaster  (Monaster)  Etheridge  (part) =Australaster 72 

P.  (Argaster)  antiqua  Hall= Mesopalseaster  ( ?)  antiquus 86 

P.  antiquatus  H&ll=Promopaldeaster  speciosus 109 

P.  antiquus  Miller=  Mesopalseaster  ( f)  antiquus 86 

P.  asperrima  Salter=  Urasterella  (?)  asperrima 187 

P.  caractaci  Salter=  Mesopalseaster  caractaci 92 

P.  clarkana  Miller =Hudsonaster  incomptus 61 

P.  clarkei  De  Koninck=  Monaster  clarkei 172 

P.  clarkei  Mi\ler=Hudsonaster  i/icomptus 61 

P.  clarki  Clarke  and  Swartz= Mesopalseaster  ( f)  clarki 94 

P.  coronella  Salter=Stenaster  (?)  coronella 167 

P.  crawfordsvillensis  Miller = Neopalseaster  crawfordsmllensis 136 

P.  dubius  Miller  and  Dyer=  Mesopalseaster  (?)  dubius 85 

P.  dyeri  1&eek=Promopal3easter  dyeri 120 

P.  eucharis  Ilfd,ll=Devonaster  eucharis 98 

P.  exculptus  M.i\\eT=Promopalseaster  exculptus 117 

P.  find  Ulrich=  Mesopalseaster  finei 81 

P.  ( Monaster)  giganteus  Etheridge =^Ltts£ratoer  giganteus 73 

P.  granti  Spencer=  Mesopalseaster  granti 89 

P.  granulosus  ILall=Promopalseaster  granulosus 112 

P.  granulosus  Meek—Promopalseaster  speciosus 109 

P.  harrisi  Miller=  Urasterella  grandis 180 

P.  hirudo  Salter=  Urasterella  hirudo 188 

P.  imbricatus  Salter=  Tetraster  (?)  imbricatus 169 

P.  incomptus  Meek.=Hudsonaster  incomptus 61 

P.  jamesi  Hall —Petraster  ( ?)  americanus 146 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  23 

Page. 

Paldeaster  longibrachiatus  Miller =Promopalxaster  spinulosus 115 

P.  magnificus  Miller =Promopal9easter  magnificus 122 

P.  matutinus  Hall=Rudsonaster  matutinus 57 

P.  miamiensis  Miller =Anorthaster  miamiensis 127 

P.  montanus  Trautschold=  Urasterella  montana 189 

P.  niagarensis  Hall 69 

P.  obtusus  Salter=Stenaster  (?)  obtusus 167 

P.  parviusculus  Billings= Mesopalseaster  ( f )  parviusculus 87 

P.  pulchellus  Billings=  Urasterella  pulchella 178 

P.  pygmsea  Eichwald.    Not  known  to  writer.    Middle  Ordovicic,  Pulkowa, 

Russia. 

P.  ruthveni  Salter=  Urasterella  ruthveni 187 

P.  shajferi  Hall= Mesopalseaster  shajferi 77 

P.  simplex  Miller  and  Dyer=Hudsonaster  incomptus 61 

P.  spedosus  Meek=Promopalseaster  spedosus 109 

P.  spinulosus  Miller  and  ~Dyer=Promopalxaster  spinulosus 115 

P.  squamatus  Salter.    Not  known  to  writer.     See  Cat.  Woodwardian  Mus.,  1873, 

p.  47;  and  Woodward,  Geol.  Mag.,  dec.  2,  vol.  1,  1874,  p.  7  (listed  only). 

Bala  of  England. 

P.  ( Monaster]  stutchburii  Etheridge=Australaster  ( ?)  stutchburii 73 

P.  wilberanus  Hall= Mesopalseaster  ( ?)  wilberanus 84 

P.  ?  wilsoni  Raymond— Promopalseaster  wilsoni 106 

P.  wyJcoffi  Miller  and  Gurley=Promopalseaster  wykoffi 119 

Palaeasterina  Gregory =Palasterina 150 

Paleeasterina  of  authors =Petraster 138 

P.  antiqua  S&lter=Lindstr6master  antiquus 149 

P.  approximata  Miller  and  Dyer=Petr aster  spedosus 142 

P.  fimbriata  Meek  and  WorthQn=Schcenaster  fimbriatus 204 

P.  rugosa  Billings— Hudsonaster  rugosus 64 

P.  spedosa  Miller  and  Dyer=Petr aster  spedosus 142 

Palaenectria  Stmtz=Palseostella 155 

P.  devonica  StiiTtz=Palssostella  solida 156 

Palaeocoma  Miller  (p^Tf)=Ptilonaster 239 

Palseocoma  S&lter=Sturtzaster 252 

Palaeocoma  (Bdellacoma)  Salter =Bdellacoma 254 

Palaeocoma  (Bhopalocoma)  SsilteT=Rhopalocoma 254 

P.  colvini  SalteT—Stiirtzaster  colvini 253 

P.  cygnipes  Salter —Sturtzaster  cygnipes 253 

P.  cylindrica  Billings=  Txniaster  cylindricus 220 

P.  marstoni  Salter= Sturtzaster  marstoni 253 

P.  princeps  MilleT=Ptilonaster  princeps 240 

P.  pyrotechnica  S&lter=Rhopalocoma  pyrote'chnica 254 

P.  spinosa  Billings=  Tssniaster  spinosus 219 

P.  vermiformis  Salter •= Bdellacoma  vermi/ormis 254 

Palseodiscus  ferox  Salter=an  echinid.     See  Jackson,  Mem.  Boston  Soc.  Nat. 

Hist.,  vol.  7,  1912,  p.  250. 

Palseophioinyxa  Sturtz • 234 

P.grandis  (Sturtz) 235 

Palseophiura  Sturtz 235 

P.  simplex  Sturtz 235 

Palaeosolaster  Sturtz 209 

P.  gregoryi  Sturtz 209 

P.  (?)  gyalum  (Clarke) 210 


24  BULLETIN   88,  UNITED  STATES   NATIONAL  MUSEUM. 


Palxosolaster  roemeri  (Clarke) 211 

Paleeospondylus  Stuitz=Palastropecten 261 

P.  zitteli  Sturtz=Palastropecten  zitteli ". 262 

Paleeostella  Stiirtz 155 

P.  solida  Stiirtz 156 

Paleespondylus  Stiirtz =Palastropecten 261 

Palaeura  Jaekel 223 

P.  neglecta,  new  species 223 

Palasteracanthion  Stiirtz=  Urasterella 173 

Palasterina  Billings  (p3tft)=Schuchertia 195 

Palasterina  McCoy 150 

P.  antiqua  SsdteT=Lindstr omaster  antiquus 149 

P.  bonneyi  Gregory 153 

P.  follmanni  Sturtz=Pseudopalasterina  follmanni 157 

P.  (?)  jamesi  D&nal=Petraster  (?)  americanus 146 

P.  kinahani  Baily=  Uranaster  kindhani 155 

P.  primseva  (Forbes) 153 

P.  (?)  ramseyensis  Hicks 154 

P.  rigidus  Billings =Petraster  rigidus 141 

P.  rugosa  Billings =Hudsonaster  rugosus 64 

P.  stellata  BillingB=Schuchertia  stellata 196 

Palasteriscus  Stiirtz 200 

P.  devonicus  Stiirtz 200 

Palastropecten  Stiirtz 261 

P.  zitteli  Stiirtz 262 

Palmipes  antiqua  Forbes= Lindstromaster  antiquus 149 

Petraster  Billings 138 

P.  (?)  americanus  (D'Orbigny) 146 

P.  (?)  antiqua  Shumard= Mesopalxaster  (?)  antiquus 86 

P.  bellulus  Billings = Mesopalseaster  bellulus 91 

P.  rigidus  (Billings) .% 141 

P.  rigidus  (Billings)  (p&Tt)=Hudsonaster  matutinus 57 

P.  smyihi  McCoy 147 

P.  spedosus  (Miller  and  Dyer) 142 

P.  wilberianus  Meek  and  Worthen=  Mesopalseaster  ( ?)  wilberanus 84 

Promopalaeaster,  new  genus 102 

P.  bellulus,  new  species 113 

P.  ^m'(Meek) 120 

P.  exculptus  (Miller) 117 

P.  granulosus  (Hall) 112 

P.  magnificus  (Miller) 122 

P.  prenuntius,  new  species 107 

P.  spedosus  (Meek) 109 

P.,  sp.  undet 108 

P.  spinulosus  (Miller  and  Dyer) 115 

P.  wilsoni  (Raymond) [ 106 

P.  wykoffi  (Miller  and  Gurley) 119 

Protaster  Forbes 224 

Protaster  Kall=Hallaster 254 

P.  f  barrisi  TL2il\=Onychaster  barrisi 272 

P.  biforis  Gregory 226 

P.  brisingoides  Gregory=Sturtzura  brisingoides 236 

P.  daoulasensis  Davy •= Fur caster  (?)  daoulasensis 261 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  25 


Protaster  decheni  Dewalque=  Tremataster  (?)  decheni 248 

P.  elegans  Parks=  Txniaster  elegans 221 

P.  flexuosus  Miller  and  DyeT=Alepidaster  flexuosus 231 

P.  forbesi  Hall= Hallaster  forbesi 255 

P.  (?)  granuliferus  lAeek=Alepidaster  granuliferus 230 

P.  (?)  gregarius  Meek  and  Worth  en =Aganaster  gregarius 264 

P.  groomi  Sollas  and  Sollas 227 

P.  leptosoma  Salter =Sturtzur  a  leptosoma 237 

P.  miamiensis  Miller =Alepidaster  miamiensis 233 

P.  miltoni  Salter—Lapworthura  miltoni 251 

P.  (Ophiura)obtususEichwald.    Unknown  to  the  writer.    See  Schichtensystem 

Esthland,  p.  193;  Lethsea  Rossica,  p.  661;   and  Woodward,  Geol.  Mag.,  dec. 

2,  vol.  1,  1874,  p.  7  (listed  only).     Siluric  of  Russia. 
P.  petri  Salter.    Unknown  to  the  writer.    See  Salter,  Cat.  Mus.  Pract.  Geol.,  p.  30; 

and  Woodward,  Geol.  Mag.,  dec.  2,  vol.  1,  1874,  p.  7  (listed  only).    Probably 

Bala,  Church  Stretton,  England. 

P.  ( f )  salteri  (Salter) 227 

P.  sedgwickii  Forbes 225 

P.  (?)  stellifer  Ringueberg 228 

P.  (?)  whiteavesianus  Parks 227 

Protasteracanthion  Stiirtz=  Urasterella 173 

P.  primus  Stiirtz=  Urasterella  asperula 188 

ProtasterinaUlrich==.47epw/as£er 228 

P .  fimbriata  Ulrich=Alepidaster  fiexuosus 231 

P.  flexuosa  3aio.eB=Alepidaster  fiexuosus 231 

Protoeuryale  C.  F.  Roemer=a  crinid. 

Protopalseaster  Hudson=  Hudsonaster 53 

P.  caractaci  Spencer= Mesopalseaster  caractaci 92 

P.  nanawayi  Hudson = Hudsonaster  narrawayi 59 

Pseudopalasterina  Sturtz 156 

P.follmanni  (Sturtz) 157 

Ptilonaster  Hall 239 

P.  princeps  Hall 240 

Bhenaster  Schondorf 133 

R.  schwerdi  Schondorf .,*. 133 

Rhodostoma  Sollas  and  Sollas =Sturtzura .7. 236 

R.  leptosoma  Sollas  and  Sol\&s=Sturtzura  leptosoma 237 

Rhopalocoma  Salter 254 

R.  pyrotechnica  Salter 254 

Roemeraster  Stiirtz=  Urasterella 173 

R.  (  ?)  acuminatus  Sturtz = Mesopalseaster  ( ?)  acuminatus 93 

R.  asperula  Stiirtz=  Urasterella  asperula 188 

Salteraster  Stiirtz=  Urasterella * 173 

S.  asperrimus  Stiirtz=  Urasterella  (?)  asperrima 187 

Schoenaster  Meek  and  Worthen 202 

S.  fimbriatus  Meek  and  Worthen 204 

S.  (?)  legrandensis  Miller  and  Gurley 206 

S.  (?)  montanus  Raymond 207 

S.,  new  species 206 

S.  (?)  wachsmuthi  Meek  and  Worthen 205 

Schuchertia  Gregory 195 

S.  laxata,  new  species 198 

S.  ordinaria,  new  species 199 


26  BULLETIN   88,  UNITED   STATES  NATIONAL  MUSEUM. 

Page. 

Schuchertia  stellata  (Billings) 196 

Siluraster  Jaekel 65 

S.  perfectus  Jaekel 66 

Spaniaster  Schondorf 95 

S.  latiscutatus  (Sandberger) 96 

Squamaster  Ringueberg 249 

S.  echinatus  Ringueberg 249 

Stenaster  Billings 163 

Stenaster  Billings  (part)=  Urasterella 173 

S.  (?)  confiuens  Trautschold 167 

S.  (?)  coronella  (Salter) 167 

S.  grandis  Meek=  Urasterella  grandis 180 

S.  huxleyi  Billings=  Urasterella  huxleyi 182 

S.  (?)  obtusus  (Forbes) 167 

8.  pulchellus  Billings=  Urasterella  pulchella 178 

S.  salteri  Billings 165 

Stiirtzaster  Etheridge 252 

S.  colvini  (Salter) 253 

8.  cygnipes  (Salter) 253 

8.  marstoni  (Salter) 253 

S.  (?)  mitchelli  Etheridge 254 

Stiirtzura  Gregory 236 

S.  brisingoides  (Gregory) 236 

S.  leptosoma  (Salter) 237 

S.  leptosomoides  Chapman 237 

Sympterura  Bather 256 

S.  minveri  Bather 256 

Tseniaster  Billings 216 

T.  australis  McCoy =Sturtzura  brisingoides 236 

T.  cylindricus  (Billings) 220 

T.  elegans  Miller 221 

T.  meafordensis  Foerste 221 

T.  schoharise.  Ruedemann 220 

T.  spinosus  (Billings). 219 

Taeniura  Gregory=  T&niaster 216 

T.  cylindrica  Gregory  =  Tseniaster  cylindricus 220 

Tetraster  Nicholson  and  Etheridge 167 

T.  asperrimus  Nicholson  and  Etheridge  =  Urasterella  (?)  asperrima 187 

T.  (?)  imbricatus  (Salter) 169 

T.  sp.  indet.  Nicholson  and  Etheridge=  Urasterella  girvanensis 186 

T.  wyville-thomsoni  Nicholson  and  Etheridge 168 

T.  wymlle-thomsoni  Nicholson  and  Etheridge  (part)  =  Hudsonaster  batheri 65 

Tremataster  Worthen  and  Miller 247 

T.  (?)  decheni  (Dewalque) 248 

T.  diffidlis  Worthen  and  Miller 247 

Trentonaster  Sturiz=Schuchertia 195 

T.  stellata  Sturtz== Schuchertia  stellata 196 

Trichotaster  plumiformis  Wright.  A  10-rayed  asterid  from  the  Wenlock  lime- 
stone at  Dudley,  England,  in  the  collection  of  Dr.  Grindrod.  Insufficiently 
described  to  be  regarded  as  defined.  See  Quart.  Journ.  Geol.  Soc.,  vol.  29, 
1873,  p.  421;  also  Woodward,  Geol.  Mag.,  dec.  2,  vol.  1,  1874,  p.  7  (listed  as 
Trochitaster  plumiformis). 

Trimerast  er  Schondorf ...  134 


BEVISION  OF  PALEOZOIC   STELLEKOIDEA. 


27 


Page. 

Trimeraster  parvulus  Schondorf 134 

Trochitaster  plumiformis  WTight=Trichotaster  plumiformis. 

Uranaster  Gregory 154 

U.  elizse,  Spencer 155 

U.  kinahani  (Baily) 155 

Uraster  hirudo  Forbes=  Urasterella  hirudo 188 

U.  obtusus  ~FoTbes=Stenaster  (?)  obtusus 167 

U.  primsevus  Forbes=PaZas£mna  primseva 153 

U.  ruthveni  Forbes=  Urasterella  ruthveni 187 

Urasterella  McCoy 173 

Urasterella  Stiirtz  I8$3=Stenaster 163 

U.  (?)  asperrima  (Salter) 187 

U.  asperula  (Roemer) 188 

U.  (?)  constellata  (Thorent) 187 

U.  girvanensis,  new  species 186 

U.  grandis  (Meek) 180 

U.  hirudo  (Forbes) 188 

U.  huxleyi  (Billings) 182 

U.  montana  (Stschurowsky) 189 

U.,  new  species 189 

U.  pulchella  (Billings) 178 

U.  ruthveni  (Forbes) 187 

U.  selwyni  McCoy 188 

U.  ulrichi,  new  species 183 

Xenaster  Simonovitsch 129 

X.  dispar  Schondorf 131 

X.  elegans  Schondorf 131 

X.  eucharis  Schondori=Devonaster  eucharis 98 

X.  margaritatus  Follmann=^".  elegans 131 

X.  margaritatus  Simonovitsch 131 

X.  margaritatus  Simonovitsch  (part)=J5T.  dispar  and  Agalmaster  grandis 131, 132 

X.  (?)  rhenanus  (Miiller) 131 

X.  simplex  Simonovitsch =Spaniaster  latiscutatus 96 

REMARKS  ON   THE   DEVELOPMENT  OF  PALEOZOIC   STELLEROIDEA. 

GEOLOGICAL. 

Distribution. — This    memoir    treats    of    the    following    Paleozoic 
Stelleroidea : 


Species. 


North 
Ameri- 
can 
species. 


Euro- 
pean 
species. 


Southern 
Hemis- 
phere 
species. 


Asteroidea... 
Auluroidea. . 
Ophiuroidea. 

Total. . . 


110 

59 

5 

174 


11 


28  BULLETIN   88,  UNITED   STATES  NATIONAL  MUSEUM. 

Arranged  geologically  the  distribution  is  as  follows : 


Ordo- 
vicic. 

Siluric. 

Devonic. 

Lower 
Carbon- 
iferous. 

Upper 
Carbon- 
iferous. 

Permic. 

Asteroidea                             

46 

16 

36 

6 

6 

0 

Auluroidea       

15 

17 

24 

3 

0 

0 

OphiuToidea 

0 

0 

0 

5 

o 

o 

Total 

61 

33 

60 

14 

6 

0 

Of  all  of  the  Paleozoic  Stelleroidea  (174  species),  not  a  single  one 
is  common  to  North  America  and  Europe.  Of  genera  having  specific 
representation  in  more  than  one  continent  there  are  the  folio  whig: 
Hudsonaster,  5  in  America,  1  in  Scotland;  Mesopalseaster,  13  (7  doubt- 
ful) in  America,  1  in  England,  ?  1  in  Germany;  Petraster,  3  in  America 
(1  doubtful),  1  in  Australia;  Stenaster,  1  in  America,  ?  1  in  Ireland  and 
Wales,  ?  1  in  England,  ?  1  in  Kussia;  Urasterella,  5  in  America,  1  in 
Scotland,  ?  1  in  Wales,  ?  1  in  France,  2  in  England,  1  in  Australia, 
1  in  Germany,  1  in  Russia;  Paldeosolaster,  1  in  Germany,  ?  1  in 
America;  Protaster,  ?  2  in  America,  1  in  England,  2  (1  doubtful)  in 
Wales;  Tremataster,  1  in  America,  ?  1  in  Belgium.  Of  Ophiuroidea, 
none  have  wide  distribution. 

Nearly  all  of  the  species  have  very  short  geologic  ranges,  but  very 
few  occurring  in  more  than  a  single  formation.  Mesopalxaster 
intermedius  ranges  from  the  ?  Utica  to  the  Maysvillian,  M.  sliafferi 
from  the  Maysvillian  to  the  Richmondian,  Alepidaster  flexuosus  from 
the  basal  Edenian  to  the  upper  Maysvillian,  Hudsonaster  incomp- 
tus  from  the  Edenian  into  the  Richmondian,  Promopalxaster  mag- 
nificus  and  Petraster  spedosus  from  the  Maysvillian  to  the  Rich- 
mondian. 

These  tables  also  show  that  the  Ophiuroidea  do  not  begin  earlier 
than  the  Lower  Carboniferous  (Burlington)  and  that  the  Auluroidea 
cease  to  exist  after  the  same  period,  for  none  are  as  yet  known  in  the 
Upper  Carboniferous  or  Permic.  The  latter  attained  their  maximum 
of  development  in  the  Siluric  and  Devonic,  with  very  rapid  decline 
in  the  Lower  Carboniferous. 

The  great  development  of  Asteroidea  in  the  Ordovicic  is  due  to  the 
marked  specific  evolution  of  the  genera  Mesopalseaster  and  Promo- 
palseaster  in  North  America.  This  knowledge  is  the  result  of  care- 
ful work  by  local  collectors  in  areas  abounding  in  good  fossils.  On 
the  other  hand  the  marked  rise  hi  specific  representation  in  the  De- 
vonic is  due  to  the  protracted  collecting  in  the  earlier  beds  of  this 
period,  the  roofing  slates  of  Bundenbach,  Germany. 

Preservation  and  occurrence. — Starfishes  are  most  often  preserved 
in  sandstones  and  muds  tones  and  least  often  in  limestones.  The 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  29 

reason  why  they  occur  less  frequently  in  limestones  is  partially 
accounted  for  by  the  fact  that  during  the  weathering  process  they 
are  almost  always  ruined.  Those  found  in  such  deposits  nearly 
always  occur  in  the  thin  shale  partings  between  the  bedded  limestones. 
In  coarse  sandstones  they  are  less  often  seen,  probably  because  these 
sediments  are  so  much  moved  by  the  storm  waves — action  that 
destroys  the  skeleton  by  separating  the  plates.  Unless  a  starfish 
is  quickly  covered  by  sediment  it  is  sure  to  be  broken  up  and  jumbled 
into  a  mass  of  unrelated  ossicles,  because  the  skeletal  parts  are  rarely 
coossified.  Hence  the  best  preserved  specimens  are  found  in  mud- 
stones  and  especially  in  the  fine-grained,  somewhat  muddy  sand- 
stones. Here  they  usually  occur  as  fine  molds,  since  all  of  the  calcium 
carbonate  has  been  dissolved  out  by  the  atmospheric  waters.  Such 
material  is  apt  to  be  fairly  abundant  in  individuals,  and  although  a 
little  difficult  to  study  is  often  well  preserved.  Its  interpretation  is 
dependent  on  artificial  casts  or  squeezes  in  wax  or  gutta-percha. 
When  found  in  black  slates,  as  at  Bundenbach,  the  skeleton  is  pre- 
served in  iron  pyrite,  and  even  though  these  sediments  have  been 
subjected  to  mountain  making,  the  specimens  can  be  cleaned  me- 
chanically of  the  adhering  slate.  The  process  is,  however,  a  laborious 
one  and  has  been  successfully  used  only  by  Stiirtz  and  his  two  prep- 
arators.  In  the  calcareous  shales  asterids  are  often  well  preserved, 
with  the  original  skeleton  more  or  less  permineralized  and  the  ossicles 
cemented  together  so  that  parts  of  the  individuals  weather  out  as 
free  fossils.  This  is  particularly  the  case  in  the  Bichmondian  deposits 
of  Ohio  and  Indiana. 

As  a  rule,  starfishes  are  obtained  in  single  specimens  and  as  acci- 
dental finds,  and  for  this  reason  they  are  among  the  rarest  of  known 
Paleozoic  animals;  they  are  the  " fancy  fossils"  of  the  local  collectors 
and  the  " choice  specimens"  of  the  museums.  All  of  this  is,  however, 
due  to  the  accident  of  preservation  plus  their  great  destruction 
through  weathering.  That  starfishes  and  ophiurids  were  common, 
though  probably  not  so  abundant  as  aulurids,  is  proven  when  they  are 
located  in  their  entombing  sediment  and  then  quarried  for.  This 
is  best  seen  in  the  well-known  Lower  Devonic  slates  of  Bundenbach, 
where  the  quarrying  for  roofing  material  has  produced  as  many 
starfishes  as  all  other  localities  put  together.  A  great  variety 
has  also  been  secured  here,  so  that  it  is  the  only  locality  and  time 
of  which  we  can  say  that  we  know  the  starfish  fauna.  The  most 
remarkable  starfish  find,  however,  is  that  made  near  Saugerties, 
New  York,  where  over  400  examples  of  the  Middle  Devonic 
Devonaster  eucharis  were  found  in  a  fine-grained,  somewhat  muddy 
sandstone,  extending  over  an  area  of  200  square  feet.  They  occur 
as  natural  molds,  and  as  the  animals  are  found  closely  associated 
with  Grammy sia,  it  is  thought  that  while  feeding  on  these  bivalves 


30  BULLETIN   88,  UNITED  STATES   NATIONAL  MUSEUM. 

they  were  suddenly  entrapped  by  the  engulfing  sand.  In  the 
crinid  bed  of  the  Keokuk  formation  at  Crawfordsville,  Indiana,  the 
ophiurid  Ony chaster  flexilis  is  also  often  met  with. 

Aulurids,  although  as  a  rule  not  well  preserved,  are  probably  more 
often  seen  than  starfishes,  and  certainly  are  far  more  abundant  than 
ophiurids.  The  latter  condition  is,  however,  probably  explained  by 
the  fact  that  no  ophiurid  is  known  older  than  the  Carboniferous. 
Of  the  aulurid  Tseniaster  elegans  31  individuals  occur  on  one  small 
slab.  It  is  probable  that  if  aulurids  and  asterids  were  systematically 
dug  for,  a  far  greater  harvest  would  result  than  that  now  at  hand. 
Whenever  such  specimens  are  found  in  place,  such  prospects  should 
be  followed  up  by  digging  or  by  prolonged  search  on  the  part  of  the 
local  workers. 

It  is  very  seldom  that  a  Paleozoic  asterid  is  so  well  preserved  that 
all  of  its  parts  can  be  made  out,  and  this  is  especially  true  as  regards 
the  dorsal  side.  During  the  decay  of  the  animals  it  is  probably 
true  that  in  most  cases  the  individual  lies  with  its  ventral  side  down, 
and  as  the  soft  parts  vanish  the  dorsal  skeleton  sinks  in  irregularly 
over  the  actinal  skeleton.  It  is  the  central  region  of  the  disk  that 
suffers  dismemberment  most.  Then,  as  the  two  sides  of  the  skeleton 
finally  come  to  be  fully  compressed,  the  rays  take  on  an  unnaturally 
great  width,  so  that  in  many  of  the  fossils  preserved  in  shales  the 
ambulacral  furrow  is  considerably  wider  than  in  nature.  For 
these  reasons  it  is  often  impossible  to  say  whether  the  ambulacralia 
are  of  the  opposite  or  the  alternate  arrangement,  and  what  was  the 
original  structure  of  the  disk  and  the  interambulacral  areas. 

ASTERID  EVOLUTION. 
GENERAL  OBSERVATIONS. 

The  majority  of  the  starfishes  studied  by  the  writer  are  from 
the  Ordovicic  strata  of  North  America.  Collectively  these  show 
considerable  evolution,  for  at  this  early  time  in  the  history  of  the 
earth  Phanerozonia,  Cryptozonia,  and  primitive  ophiurids  (  =  Aulu- 
roidea)  are  present.  Even  near  the  base  of  the  Middle  Ordovicic 
the  two  former  groups  appear  to  be  equally  common,  while  the 
aulurids  are  as  a  rule  rare  and  small,  though  there  are  occasional 
large  ones.  Here  the  primitive  phanerozonian  asterids  are  also  small, 
hardly  ever  exceeding  15  mm.  in  diameter,  while  the  derived  and 
far  more  complex  Cryptozonia  are  large,  some  of  them  having  rays 
exceeding  50  mm.  In  the  Lower  Ordovicic  of  America  no  starfishes 
are  known,  while  the  few  that  have  been  reported  from  Great  Britain 
appear  to  the  writer  to  be  from  the  Middle  Ordovicic. 

These  facts  show  that  in  spite  of  their  absence  in  Lower  Ordovicio 
rooks  tjfcere  must  have  lived  at  that  time  various  kinds  of  starfishes^ 


REVISION  OF  PALEOZOIC   STELLEEOIDEA.  31 

Not  only  this,  but  we  may  confidently  add  that  the  varied  organi- 
zation of  those  of  the  Middle  Ordovicic  proves  that  there  is  a  long 
previous  history  of  which  paleontology  knows  nothing.  The  origin 
of  the  Asteroidea  goes  back  in  all  probability  to  the  Proterozoic,  as 
may  be  inferred  from  the  complex  metamorphosis  of  the  starfish 
larva.  In  all  of  the  Cambric,  however,  not  a  single  starfish  has  been 
found,  and  this  is  the  more  surprising  when  one  considers  the  abun- 
dance of  life  unearthed  from  these  sediments  in  so  many  places 
throughout  the  world.  This  may  mean  that  a  preservable  starfish 
skeleton  was  not  evolved  until  Lower  Ordovicic  time,  where  they 
will  surely  be  found. 

TJie  most  primitive  fossil  starfish. — Of  the  Ordovicic  starfishes,  the 
genus  Hudsonaster  is  the  most  primitive,  but  with  the  full  quota  of 
parts  in  the  primary  skeleton  that  an  unmodified  or  unspecialized 
starfish  must  have.  Among  living  starfishes  this  primitive  skeleton 
is  rarely  seen,  but  occurs  in  Heterasterias  volsellata,  "and  in  a  few 
other  species,  especially  when  young"  (Verrill  1914:27).  There  are 
other  genera  with  a  simpler  skeleton  (Stenaster  and  Tetraster),  but  these 
are  clearly  cryptozonian  forms  that  have  originated  in  a  phanerozonian 
stock  not  unlike  Hudsonaster.  The  oldest  Hudsonasters  (see  plates  1  to 
6)  are  small  animals  about  10  mm.  in  diameter,  with  thick,  highly  con- 
vex, closely  adjoining  plates,  all  of  which  are  devoid  of  spines  ex- 
cepting the  adambulacrals,  which  have  simple,  minute,  articulating 
spines.  On  the  ventral  side  there  are  in  each  radius  double  columns 
of  rectangular  ambulacralia,  with  the  pieces  of  each  ambulacrum 
arranged  opposite  to  one  another,  or  nearly  so.  Outside  of  these  are 
single  columns  of  adambulacralia  of  about  the  same  number  as  the 
ambulacrals;  they  are,  however,  somewhat  larger  and  more  trans- 
verse. These  are  laterally  bounded  by  much  larger,  highly  convex, 
granulated,  very  prominent  marginals,  which,  as  they  border  the 
animals  and  are  simple  ossicles  (there  are  not  here  two  superposed 
marginalia  as  is  so  common  in  living  forms),  are  the  inframarginal 
columns.  In  the  axils  of  the  rays  lies  a  single  large  marginal  plate, 
the  axillary,  and  these  occupy  the  entire  interbrachial  areas.  Around 
the  inner  sides  of  these  axillaries  the  adambulacralia  continue,  the 
two  basal  pieces  being  the  largest  and  the  essential  elements  of  the 
oral  armature.  All  of  the  ventral  ossicles  are,  therefore,  seen  to  be 
of  the  primary  skeleton. 

On  the  dorsal  side  of  Hudsonaster,  the  rays  have  medially  promi- 
nent columns  of  radials,  while  on  each  side  of  these  are  other  columns 
of  thick  ossicles,  alternating  with  the  radialia,  and  these  are  the 
supramarginals.  The  former  ossicles  continue  closely  adjoining  to 
near  the  center  of  the  disk,  where  lies  a  single  large  plate  usually  called 
in  this  memoir  the  central  disk  plate,  or,  more  rarely,  the  centro-dorsal. 
In  the  same  way,  the  supramarginals  abut  in  the  axils  upon  a  single 

50601°— Bull.  88—15 3 


32  BULLETIN   88,  UNITED   STATES  NATIONAL  MUSEUM. 

large  ossicle,  the  basal  supramarginal  plate.  It  is  thought  that  the 
ancestors  of  Hudsonaster  had  a  dorsal  disk  skeleton  made  up  of  a 
centro-dorsal,  a  first  ring  of  5  primordial  radials,  and  a  second  ring 
of  10  plates,  5  of  which  are"  the  second  radials,  and  5  interradial 
pieces,  the  primordial  supramarginals.  In  Hudsonaster,  however, 
some  progression  has  taken  place  in  the  disk  in  the  way  of  increase 
of  size.  Therefore  additional  ossicles  of  the  secondary  skeleton  have 
developed  to  take  up  this  space,  these  accessory  disk  pieces  being 
inserted  between  the  centro-dorsal  and  the  first  ring  of  primordial 
radials.  Such*  a  development  of  a  small  number  of  accessory  pieces 
here  is  a  hint  of  future  complexity  and  the  rise  of  the  secondary  skel- 
eton, and  we  shall  see  how  in  later  and  derived  genera  their  number 
becomes  multitudinous  and  their  places  of  insertion  nearly  everywhere 
in  the  older  portions  of  the  skeleton  between  the  columns  of  ossicles. 

The  supramarginals  do  not  margin  the  animals,  but  lie  inside  the 
inframarginals  and  axillaries  which  do  margin  Hudsonaster  and  most 
of  the  Paleozoic  asterids. 

From  Hudsonaster  to  all  other  progressive  asterids  of  the  Phane- 
rozonia  type,  the  change  lies  mainly  in  the  increasing  number  of  the 
ossicles,  relative  decrease  in  the  size  of  the  plates,  introduction  of 
many  new  series  of  Accessory  pieces,  absorption  and  removal  of 
others,  with  a  marked  general  tendency  to  break  up  the  stiff  and 
ponderous  inherited  skeleton  into  one  of  small  pieces,  thus  affording 
greater  flexibility  and  greater  podial  strength  through  the  endless 
duplication  of  ambulacral  parts.  These  developmental  tendencies 
take  place  more  especially  on  the  dorsal  area  and  are  further  accent- 
uated through  increase  of  body  cavity,  which  demands  an  enlarged 
skeletal  covering.  The  disk  widens,  and  along  with  it  the  proximal 
parts  of  the  rays,  so  that  interbrachial  areas  are  also  affected,  until 
finally  in  more  than  one  phylum  pentagonal  asterids  result.  The 
interbrachial  areas  are  dorsaUy  increased  by  the  insertion  of  acces- 
sory pieces  between  the  infra-  and  supramarginalia,  and  ventrally 
by  the  crowding  into  these  areas  of,  first,  the  single  axillaries,  and 
then  more  and  more  of  the  oldest  inframarginals  in  pairs,  assisted 
also  here  by  the  development  of  accessory  ossicles. 

Origin  of  the  wriggling  type  of  starfish. — From  Hudsonaster  to  the 
other  progressive  asterids  of  the  Cryptozonia  type  the  evolutionary 
tendencies  are  in  the  same  directions,  but  here  even  greater  flexibility 
appears  to  be  the  main  stimulus.  Accordingly,  the  entire  dorsal  skel- 
eton tends  to  break  up  into  small  loosely  adjoining  pieces  and  finally 
even  into  a  spicular  spinose  mesh.  In  these  forms  the  ossicles  of  the 
primitive  columns  are  no  longer  discernible  as  such,  and  this  tendency 
is  very  apt  to  be  likewise  true  of  the  primordial  disk  plates.  On  the 
ventral  side  the  inframarginals  are  no  longer  wholly  present  as  such, 
but  may  be  here  mixed  up  with  the  dorsal  skeletal  complex.  How- 


EEVISION   OF  PALEOZOIC   STELLEKOIDEA.  33 

ever,  some  of  these  plates  are  at  times  retained  in  the  interbrachial 
areas  as  large  pieces,  and  in  many  forms  they  are  still  to  be  made 
out  clearly  on  the  sides  of  the  growing  distal  ends  of  the  rays.  Here 
the  inframarginals  occur  as  columns  of  tiny  closely  adjoining  ossicles 
situated  directly  beside  the  adambulacrals,  and  in  a  few  cases  the 
whole  five  primary  dorsal  columns  (one  radial,  two  supramarginal,  and 
two  inframarginal)  can  be  made  out  without  any  accessory  pieces  be- 
tween them.  In  other  words,  a  Paleozoic  cryptozonian  may  retain 
the  marginals  throughout  life,  but  because  of  their  small  size  and 
isolation  one  from  another  by  accessory  pieces  or  because  of  intense 
spiculization,  they  are  no  longer  recognizable  as  such.  The  classifies  - 
tory  value  of  the  presence  or  absence  of  marginalia  is  discussed  else- 
where (under  Cryptozonia),  and  as  the  inframarginals  are  seemingly 
or  actually  lost  independently  in  a  number  of  phyla  the  term  is 
here  used  as  expressive  of  this  condition,  and  not  necessarily  of 
relationship. 

Spencer  (1914:9)  takes  up  the  origin  of  the  wriggling  habit  from 
another  point  of  view,  that  is,  from  a  study  of  living  Stelleroidea  as 
described  by  MacBride.  The  former  states  that  the  living  forms  can 
be  grouped  into  two  divisions  as  follows : 

The  graspers. — Asteroid  forms  in  which  the  tube-feet  are  used  for  walking,  and  for 
grasping  and  pulling  open  the  bivalve  shells  of  the  mollusks  upon  which  they  usually 
feed.  The  ambulacralia  form  an  arch  to  take  the  pull. 

The  wrigglers. — Ophiuroid  forms  in  which  the  tube-feet  have  lost  locomotory  powers 
and  become  much  reduced.  The  animals  progress  by  wriggling  movements  of  the 
arm,  and  the  ossicles  of  the  ambulacral  groove  are  extensively  modified  for  this  pur- 
pose. The  food  is  pushed  into  the  mouth  by  the  first  two  pairs  of  tube-feet,  which 
become  considerably  enlarged  and  are  known  as  buccal  tentacles. 

If  we  trace  the  history  of  the  forms  backward  we  find  that  the  difference  between 
them  tends  to  disappear.  Both  the  ' '  graspers } '  and  the  ' '  wrigglers ' '  descended  from 
a  third  group,  which  I  call  provisionally  "the  primitive  Asterozoa." 

The  postulated  " primitive  Asterozoa"  above  referred  to  are  based 
upon  the  earliest  stages  of  growth  of  starfishes,  and  had  the  following 
characters.  The  animals  were  attached  to  the  ground  by  a  well- 
developed,  flexible  stalk  (seen  in  Asterina  and  Asterias);  the  disk 
was  small  compared  with  the  five  arms.  In  connection  with  the 
water-vascular  system  there  were  two  series  of  ossicles,  (1)  a  double 
column  of  flooring  pieces  forming  the  sides  of  the  ambulacrum,  and  (2) 
a  paired  covering  series  as  a  protection  to  the  soft  structures  under- 
neath. The  podia  emerged  between  the  flooring  pieces  and  these  at 
first  "were  arranged  not  exactly  opposite  to  each  other,  but  slightly 
alternating,  and  in  consequence  we  find  that  both  the  flooring  and 
covering  plates,  which  are  in  direct  association  with  the  podia,  are 
not  exactly  opposite,  but  arranged  alternately. " 


34 


BULLETIN   88.  UNITED   STATES  NATIONAL  MUSEUM. 


The  rays  terminated  in  a  single  ossicle  with  an  unpaired  tube-foot 
that  later  developed  at  its  outer  end  a  pigment  spot  and  finally  an 
"eye." 

At  last  the  animal  lost  the  stalk  and  moved  about  freely  as  the 
primitive  asterozoon.  The  flooring  plates  changed  into  ambulacralia 
and  the  roofing  plates  into  adambulacralia,  while  the  tube-feet  were 
used  not  for  grasping  and  crawling  but  for  passing  small  particles  of 
food  to  the  mouth. 


Inf 


Ax 


FIGS.  1  AND  2.— VENTRAL  AND  DOKSAL  VIEWS  OF  THEORETIC  PHYLEMBRYO  OF  STELLEROIDEA,  INDICATING 

HOW  THE  RAYS  ARE  INTRODUCED.  BASED  ON  HUDSONASTER.  A  d,  ADAMBULACRALS;  Am,  AMBULA- 
CKALS;  AX,  MARGINAL  AXILLARIES;  CZ>,CENTRO-DORSAL;  /72/,INFRAMARGINALS;  Rl , PRIMORDIAL  RADIALS: 
R2  TO  Rll,  SUBSEQUENT  RADIALSJ  Sml ,  DORSAL  INTERRADIALS  OR  PRIMORDIAL  SUPRAMARGINALSJ  Sm2 
TO  SmlO,  SUBSEQUENT  SUPRAMARGINALS. 

The  asterid  radicle. — Hudsonaster  is  held  to  be  very  near  the  radicle 
that  gave  rise  through  modification  and  inheritance  to  all  subsequent 
Stelleroidea.  A  study  of  the  various  species  and  specimens  of  Hud- 
sonaster, reinforced  by  the  chronogenesis  of  this  genus  and  the  de- 
velopmental stages  in  the  individuals,  which  are  discernible  in  the 
youthful  distal  ends  of  the  rays  when  contrasted  with  the  mature 
proximal  region  of  the  same,  has  led  the  writer  to  speculate  on  the 
probable  skeletal  characters  of  the  radicle  of  the  Stelleroidea.  An 
analysis  of  mature  H.  matutinus  and  of  half-grown  H.  incomptus 
shows  that  their  ancestors  must  have  been  devoid  of  all  disk  accessory 
pieces,  or  for  that  matter  of  all  secondary  ossicles,  since  it  appears 
that  it  is  on  the  disk  that  these  plates  first  arise.  Further,  the 
same  material  indicates  that  the  younger  the  individual  specimen, 
or  the  older  the  species  geologically,  not  only  the  smaller  is  the 
specimen,  but  the  fewer  plates  has  it  in  any  column.  As  the 


REVISION   OF  PALEOZOIC   STELLEROIDEA. 


35 


ossicles,  other  than  those  of  the  disk,  the  interbrachial  areas,  and  the 
accessory  pieces,  are  introduced  in  all  the  columns  at  the  distal  ends 
of  the  rays,  we  are  permitted,  in  theorizing  as  to  the  characters  of  the 
radicle,  and  from  what  has  been  learned  from  Hudsonaster,  to  elimi- 
nate all  of  the  rays  with  their  ventral  and  dorsal  ossicles  down  to 
the  disk.  If  this  is  done,  there  finally  results  a  tiny  depressed  and 
mammillated  spheroid,  made  up  dorsally  of  11  primary  plates,  and  5 
marginal  axillaries,  and  ventrally  of  a  limited  number  of  adambu- 
lacrals  and  ambulacrals  around  the  mouth.  To  make  this  matter 
clearer,  two  diagrams  are  presented  of  the  probable  characters  of  the 
direct  ancestor  of  Hudsonaster  (see 
figs.  1  and  2) . 

By  taking  away  the  rays  down  to 
near  their  bases,  i.  e.,  to  R2,  and 
correspondingly  decreasing  the  size 
of  the  primordial  supramarginals,  we 
get  the  dorsal  structure  of  a  late  stage 
of  the  probable  typembryo  of  the 
Stelleroidea,  as  illustrated  in  fig.  3. 

If  all  of  the  ray  plates  are  com- 
pletely removed,  we  apparently  get 
the  typembryo  of  the  class  Stelle- 
roidea, as  iUustrated  in  figs.  4  and 

5.      It  Should   be  Stated   here,   how-    FlG-  S.-DORSAL  VIEW  OF  THEORETIC  TYPEM- 
,,         t,  ,  .   ,,  BRYO  OF  STELLEROIDEA  AT  THE  BEGINNING 

ever,  that  the  number  of  the  adam- 
bulacrals  and  ambulacrals  in  figure 
5  is  entirely  conjectural,  though 
these  plates  and  those  of  the  mouth 
frame  are  among  the  first  to  develop 
in  living  forms. 

If  the  developmental  views  just  stated  are  correct,  it  follows  that 
the  five  branches  of  the  water- vascular  and  nerve  rings  of  the  typ- 
embryo of  Stelleroidea  grow  outward  along  the  radii,  developing  as 
they  grow  the  rays  or  arms  with  their  dorsal  and  ventral  skeletons. 
In  other  words,  the  growing  tips  of  the  radii  spread  outward  beyond 
the  disk,  and  each  one  gives  rise  to  nine  columns  of  ossicles  (one 
radial,  two  supramarginal,  two  inframarginal,  two  adambulacral  and 
two  ambulacral) .  The  radial  plates  continue  as  simple  columns,  while 
upon  the  primordial  supramarginals  and  the  axillaries  rest  pairs 
of  columns,  the  supramarginals  and  inframarginals,  respectively. 

In  Echini,  however,  the  growing  tips  of  the  radii  do  not  spread 
beyond  the  disk  (apical  disk  of  oculars  and  genitals)  but  remain 
internal  and  give  rise  to  new  ossicles,  the  ambulacrals  (same  ossicles 
in  Stelleroidea)  and  interambulacrals  ( =  adambulacrals  of  Steller- 


OF  RAY  DEVELOPMENT.  THE  PRIMORDIAL  SUP- 
RAMARGINALS HERE  HAVE  ON  EACH  SIDE  THE 
BASAL  PIECES  OF  TEN  SUPRAMARGINAL  COL- 
UMNS. CD,  CENTRO-DORSAL;  Rl,  PRIMORDIAL 
RADIAL;  R2,  SECOND  RADIAL;  Sml,  DORSAL  IN- 

^ERRADIAL  OR  PRIMORDIAL  SUPRAMARGINAL; 
82,  BEGINNING  OF  SUPRAMARGINAL  COLUMNS. 


36 


BULLETIN 


UNITED   STATES   NATIONAL   MUSEUM. 


oidea),  all  of  which  appear  from  underneath  the  ventral  edges  of 
the  oculars,  each  plate  in  turn  being  pushed  orally1. 

In  any  event,  whatever  the  pre-Hudsonaster  evolution  was,  we 
are  on  safe  ground  in  indicating  what  the  developmental  changes 
were,  starting  with  this  genus.  We  will  not  take  up  all  of  the  skele- 
tal parts  and  discuss  them  in  detail,  but  will  attempt  only  the  more 
essential  portions. 

Ontogeny. — Ontogenetic  stages  of  development  in  the  ossicles 
of  asterids  can  readily  be  made  out  to  some  extent  in  any  well  pre- 
served specimen.  The  variations  can  best  be  seen  in  those  forms 
with  the  least  number  of  plates  and  therefore  in  the  more  primitive 
genera.  Here  all  of  the  primary  ossicles  are  introduced  at  the  tips 
of  the  rays  in  the  seven  primary  columns.  The  youngest  pieces  are 
also  the  smallest  and  the  simplest.  At  first  they  are  globular, 


FIGS.  4  AND  5.— DORSAL  AND  VENTRAL  VIEWS  OF  THEORETIC  TYPEMBRYO  OF  STELLEROIDEA.  Ax,  VEN- 
TRAL OR  MARGINAL  AXILLARIES  OR  BASAL  INFRAMARGINALS;  CD,  CENTRO-DORSALJ  R,  PRIMORDIAL 
RADIALSJ  Sml,  DORSAL  INTERRADIALS  OR  PRIMORDIAL  SUPRAMARGINALS. 

smooth,  and  loosely  adjoining.  Tracing  them  down  the  columns, 
the  specific  characters  are  seen  to  develop  and  finally  the  basal  pieces 
are  found  to  be  the  most  modified  of  all.  This  is  particularly  true 
of  the  dorsal  columns  where  the  most  ornate  plates  are  the  oldest. 
In  the  different  species  of  Hudsonaster  one  can  also  trace  the  changes 
chronogenetically,  as  for  instance  in  the  basal  radialia  and  supra- 
marginalia.  In  the  oldest  species  these  plates  are  not  at  all,  or  but 
very  slightly  stellate,  more  so  in  H.  incomptus,  and  most  so  in  the 
youngest  and  largest  species,  H.  rugosus. 

In  the  stocks  with  more  complex  skeletons,  the  ontogenetic  varia- 
tions in  the  plates  can  be  traced  in  the  same  way.  However,  as  these 
forms  almost  always  have  more  or  less  of  accessory  plates  that  are 
introduced  nearly  throughout  the  entire  skeleton  during  the  juvenile 
growth  and  even  at  maturity,  the  study  is  complicated  by  the  inter- 
mixture of  ossicles  of  varying  age. 

i  See  Jackson,  Phytogeny  of  the  Echini,  Mem.  Boston  Soc.  Nat.  Hist.,  vol.  7, 1912. 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  37 

Spinosity  can  also  be  studied  ontogenetically  because  the  youngest 
ossicles  do  not  have  spines,  and  when  these  appear  they  are  smaller 
and  less  characterized  than  the  older  ones  situated  in  the  proximal 
portions  of  the  columns. 

Many  of  the  ontogenetic  changes  observed  by  the  writer  are  re- 
corded throughout  this  work,  and  their  significance  in  related  species 
and  genera  has  been  made  use  of  in  discerning  the  phylogenetic 
lines  of  descent. 

Regeneration. — Among  living  starfishes  it  is  common  to  regrow 
arms  that  have  been  lost  through  accidental  causes.  From  the 
base  of  the  severed  ray  a  new  growing  tip  is  established,  forming 
a  juvenile  arm  that  gradually  grows  to  full  size  and  assumes 
mature  characteristics.  Schondorf  (1909a:  96-97)  states  that  this 
habit  has  been  pronounced  since  the  Jurassic  but  that  he  has  failed 
to  find  marked  regeneration  in  Paleozoic  asterids.  He  did,  how- 
ever, note  partial  replacement  of  minor  losses  among  the  Devonic 
species.  Stiirtz,  who  has  handled  more  Paleozoic  asterids  than  any 
other  paleontologist,  also  has  not  noted  a  single  case  of  marked 
regeneration.  The  same  is  true  for  the  400  Devonaster  eucJiaris 
found  in  a  limited  area  of  the  Middle  Devonic  of  New  York. 
Clarke,  in  describing  this  find  (1912:  44-45),  however,  does  note  a 
few  specimens  "  which  show  the  existence  of  only  four  instead  of 
the  normal  five  arms."  These  are  the  only  examples  of  four-rayed 
Paleozoic  starfishes  so  far  recorded. 

The  writer  has  also  been  unable  to  find  a  single  case  of  regenera- 
tion, but  in  the  Middle  Ordovicic  cryptozonian  Urasterella  ulrichi 
he  describes  a  specimen  with  two  normally  developed  rays  and  three 
short  stumps.  All  of  the  arms  are  normal  for  the  species,  except 
for  the  length  of  three  rays  and  their  terminations,  which  are  blunt. 
(See  pi.  29,  fig.  1.)  It  seems  to  him  that  this  occurrence  is  not  due 
to  the  accident  of  fossilization  or  weathering,  but  is  an  actual  case 
of  loss  in  life  with  subsequent  healing  of  the  wounds,  but  without 
regeneration  of  the  lost  parts. 

During  most  of  the  Paleozoic,  the  starfishes  could  have  had  no 
carnivorous  enemies  other  than  the  cephalopods;  as  for  marine 
fishes,  the  armored  Arthrodires  did  not  appear  until  the  Middle 
Devonic,  while  the  ancient  sharks  were  not  common  until  Lower 
Carboniferous  (Mississippi)  time.  It  is  possible  that  regeneration 
among  the  starfishes  is  connected  with  the  rise  of  carnivorous  ene- 
mies, but  as  the  habit  is  so  common  among  living  forms  it  is  more 
probable  that  this  power  has  always  been  inherent  in  the  class. 
Regeneration  among  the  crinids  has  been  noted  in  several  cases 
where  lost  distal  ends  of  arms  were  being  replaced  by  immature 
growths.  Such  have  been  seen  in  the  Lower  Carboniferous  (Bur- 
lington and  Keokuk  formations)  of  America. 


38  BULLETIN   88,  UNITED   STATES   NATIONAL  MUSEUM. 

Number  and  character  of  rays. — In  the  geologically  oldest  and  the 
most  primitive  asterids  as  well  there  are  always  5  rays,  no  multirayed 
form  being  known  back  of  the  middle  of  Siluric  time.  In  the  most 
primitive  genus  of  Phanerozonia,  Hudsonaster,  the  rays  are  short  and 
stout,  there  is  a  large  disk  without  interbrachial  arcs,  and  the  skele- 
ton is  simple  but  ponderous.  From  this  type  originate  those  with  5 
slender  rays  and  also  forms  with  more  or  less  large  interbrachial  arcs, 
the  pentagonal  starfishes. 

Long,  slender,  and  flexible-rayed  genera  without  marginalia  are 
present  as  early  as  the  most  primitive  Phanerozonia,  i.e.,  as  early  as 
the  older  Middle  Ordovicic,  indicating  that  the  two  main  types  of 
asterid  development  arose  still  earlier.  The  same  is  true  for  the 
ophiurid  ancestors  (Auluroidea).  In  fact,  slender-rayed  Crypto- 
zonia  are  more  commonly  seen  in  the  Middle  Ordovicic  than  are  the 
Phanerozonia. 

Multi-rayed  Phanerozonia  with  primitive  arm  construction  appear 
in  the  Middle  Siluric  (Wenlock)  in  Lepidaster.  This  genus  has  rays 
which  are  short  and  stout,  reminding  one  in  this  respect  strongly 
of  the  primitive  5-rayed  forms.  An  insufficiently  described  10- 
rayed  form  (Trichotaster  plumiformis)  is  recorded  from  the  Middle 
Siluric  (Wenlock)  of  England.  In  Helianihaster  of  the  Lower  Devonic 
there  are  from  14  to  16  rays  and  here  they  are  long  and  slender, 
while  in  the  Upper  Devonic  there  is  a  form  with  only  1 1  rays.  Lepid- 
astereUa  of  the  Upper  Devonic  has  24  arms. 

All  of  the  multi-rayed  Cryptozonia  have  slender  rays  and  rather 
large  disks.  None  are  older  than  the  Lower  Devonic,  where  Medusaster 
has  from  12  to  15  rays,  Echinasterias  25,  Palxosolaster  27  to  29 
(an  Upper  Devonic  species  referred  doubtfully  to  this  genus  has  24 
or  25) ,  Echinostella  28  or  29,  and  Echinodiscaster  29. 

Curiously,  no  multi-rayed  starfish  is  known  hi  the  Paleozoic  later 
than  the  Devonic.  Further,  the  arms  may  be  either  odd  or  even  in 
number  in  the  same  genus  or  even  species.  How  the  living  multi- 
rayed  starfishes  introduce  their  rays  is  explained  under  Palseosolas- 
teridse  (p.  207). 

Verrill  (1914:  12-17)  holds  that  the  multi-rayed  forms  arose  as 
"  '  sports/  which  have  persisted  by  heredity  and  natural  selection 
because  they  were  advantageous."  The  advantage  lay  in  "the 
increased  number  of  ambulacral  sucker-feet. "  Most  of  these  forms 
are  now  living  in  shallow  water  among  the  rocks  exposed  to  the  surf. 
He  states:  "  This  is  true  of  the  seven  species  of  Heliaster,  with  very 
numerous  rays;  and  of  Pycnopodia,  with  20  to  24  rays;  and  of  the 
various  shallow-water  and  littoral  species  of  Solaster  and  Crossaster, 
which  usually  have  9  to  15  rays  (rarely  8  or  less).  It  is  also  true  of 
the  numerous  6-rayed  species  of  Asterias,  Pisaster,  and  allied  genera." 


REVISION  OF  PALEOZOIC   STELLEKOIDEA.  39 

On  the  other  hand,  the  increase  of  rays  is  more  probably  due  "  to 
the  advantage  gained  in  holding  their  food  securely,  and  in  opening 
bivalves,  than  for  holding  to  the  rocks,  though  both  go  together." 

"The  ability  to  cling  tenaciously  to  rocks  may  be  perfected  in 
other  ways,  involving  equally  an  increased  number  of  sucker-feet. 
This  is  often  attained  by  lengthening  the  rays,  *  *  *  by  crowding 
the  suckers  into  more  than  four  rows,  *  *  *  and  by  increasing 
the  size  and  strength  of  the  suckers." 

DEVELOPMENT  or  THE  PARTS. 

Anus. — In  all  living  starfishes  the  anus  apparently  lies  in  the  next 
interradius  to  the  right  of  the  madreporite,  or  in  the  direction  as  the 
clock  goes,  but  in  no  Paleozoic  asterid  is  there  positive  evidence  of 
an  anal  opening.  However,  it  is  extremely  rare  in  these  forms  to  find 
the  disk  so  well  preserved  as  to  make  it  possible  to  locate  so  small 
an  orifice.  In  certain  specimens  of  Hudsonaster,  immediately  adj acent 
to  the  centro-dorsal  plate,  there  is  an  open  space  that  either  is  the 
anal  opening  or  where  a  plate  has  dropped  out  in  fossilization. 
Schondorf  has  also  failed  to  find  this  structure  in  the  German  Paleo- 
zoic asterids,  but  has  indicated  its  probable  position  in  Spaniaster 
(see  fig.  8)  and  Calliasterella. 

Madreporite. — In  more  than  half  of  the  Paleozoic  asterids  the 
madreporic  plate  has  not  been  seen.  In  many  cases  this  is  due  to  the 
infallen  condition  of  the  disk  skeleton  and  the  jumbled  state  of  the 
ossicles;  in  others  it  is  due  to  the  fact  that  it  is  so  small  as  not  to  be 
readily  distinguished  among  the  mass  of  other  small  plates.  Finally, 
a  great  number  of  asterids  are  known  only  from  the  actinal  side. 

The  madreporite  in  size  varies  from  minute  to  very  large  and 
ponderous.  It  may  be  round,  oval,  or  many-sided,  concave,  and 
depressed  beneath  the  disk  pieces,  or  protruding  cone-shaped  (Petras- 
ter) .  As  a  rule,  it  is  marked  by  striations  that  are  coarse  or  very  fine, 
straight  or  wavy  lined,  or  it  may  be  crenulostriate  or  with  granular 
surface.  In  Petraster  the  surface  canals  enter  into  two  spirals  that 
carry  the  water  into  the  stone  canal.  In  living  forms  with  more 
than  six  rays  there  may  be  two  or  more  madreporites,  but  in  no 
Paleozoic  species  has  more  than  one  been  seen. 

In  all  of  the  Paleozoic  phanerozonians  the  madreporite  appears 
to  be  always  dorsal  in  position.  In  the  most  primitive  genus,  Hud- 
sonaster, the  plate  may  be  large  and  conspicuous  or  at  times  can  not 
be  made  out  even  when  the  disk  is  fairly  well  preserved.  In  no 
Mesopalseaster  has  this  sieve  plate  been  seen,  although  good  speci- 
mens are  at  hand,  a  condition  probably  due  to  its  small  size  among 
the  small  skeletal  pieces  of  this  genus.  In  Spaniaster  it  is  very  small. 
In  Promopalseaster  the  madreporite  is  usually  conspicuous  and  large, 


40  BULLETIN   88,  UNITED  STATES   NATIONAL  MUSEUM. 

and  the  same  is  true  for  Xenaster  and  Agalmaster.  The  plate  is  also 
known  in  Palseaster,  Devonaster,  Neopalseaster,  and  Palasterina. 

In  multi-rayed  phanerozonians  the  madreporite  is  unknown  in 
Lepidaster  and  Lepidasterella.  In  Helianthaster  it  is  large,  conspic- 
uous, and  situated  on  the  edge  of  the  disk,  more  actinal  than  abac- 
tinal.  On  the  other  hand,  in  the  cryptozonian  multi-rayed  genera 
the  madreporite  is  apparently  always  actinal  and  more  or  less  large, 
as  in  Palseosolaster  and  Echinodiscaster.  This  plate  is  probably  also 
always  actinal  on  large-disked  Cryptozonia  such  as  Palasteriscus 
(plate  enormously  large),  and  OJieiropteraster  (here  small  and  situ- 
ated near  the  mouth) . 

Among  the  five-rayed  Paleozoic  cryptozonians  the  madreporite 
is  known  only  in  Monaster  (large) ,  Urasterella  (medium) ,  and  Jaekel- 
aster  (small) .  In  all  it  is  always  on  the  abactinal  area. 

From  this  evidence  we  see  that  in  the  five-rayed  Phanerozonia, 
forms  that  are  more  or  less  rigid,  the  madreporite  is  always  on  the 
dorsal  or  upper  side  of  the  animals,  this  being  true  for  the  deeply 
stellate  as  well  as  for  the  pentagonal  species.  In  the  multi-rayed 
genera,  however,  there  is  a  marked  tendency  for  this  plate  to  move 
outward  to  the  edge  of  the  disk.  In  the  five-rayed  cryptozonians 
the  madreporite  so  far  as  known  is  always  dorsal,  but  in  the  large- 
disked  or  pentagonal  forms  and  the  multi-rayed  species  this  plate  is 
apparently  always  ventral. 

Spencer  (1914:35-38)  says  that  "many  Paleozoic  Asterozoa  do  not 
appear  to  have  a  madreporite"  and  he  is  "inclined  to  regard  this, 
in  these  old  forms,  as  usually  a  primitive  feature."  The  present 
writer,  it  is  true,  states  above  that  in  more  than  half  of  the  Paleo- 
zoic asterids  the  madreporic  plate  has  not  been  seen.  This  is  due  in 
most  cases,  however,  to  poor  preservation,  and  in  others  to  the  fact 
that  the  plate  is  so  much  like  the  other  disk  plates  as  not  to  be  dis- 
tinguishable from  chem.  Spencer  concludes  further  that  it  appears 
that  the  madreporite  originated  on  the  ventral  side,  or  at  least  was 
marginal,  in  the  primitive  forms,  and  that  it  passed  over  in  later 
Asteroidea  to  the  dorsal  side.  In  Eudsonaster  we  have  the  most 
primitive  known  starfish,  and  here  in  H.  incomptus  it  is  a  large  and 
conspicuous  plate  on  the  abactinal  side.  Further,  the  evidence  of 
the  Paleozoic  starfishes  (Phanerozonia),  so  far  as  the  present  writer 
knows  them,  is  that  this  plate  is  always  dorsal  in  position,  and  he  is 
inclined  to  the  view  that  all  of  them  had  the  madreporite,  that  it 
originated  on  this  side,  and  that  in  later  cryptozonian  multiradiate 
forms  it  moved  outward  to  the  margin  of  the  disk  or  to  the  actinal 
surface.  In  regard  to  the  Auluroidea,  the  writer  has  seen  the 
madreporite  so  rarely  that  no  deductions  as  to  its  original  position 
in  these  forms  can  be  made. 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  41 

Spinosity. — In  general,  it  can  be  said  that  spines  are  least  developed 
in  the  heavily  plated  Phanerozonia,  more  so  in  those  forms  where 
the  dorsal  skeleton  is  made  up  of  small  ossicles  in  abundance,  and 
fully  in  most  of  the  Cryptozonia  stocks. 

In  primitive  Hudsonaster,  all  of  the  plates  other  than  the  am- 
bulacrals  are  more  or  less  well  tuberculated,  and  these  granules  do 
not  now  carry  spines,  if  they  ever  did.  In  later  forms,  however,  as 
Promopalseaster,  they  may  all  have  borne  spines,  some  of  them  of 
large  size.  Small  club-shaped  spines  occur  here  in  considerable 
abundance  along  the  sides  of  the  inframarginals  and  the  adambula- 
crals.  In  Palseaster  there  are  brushes  of  delicate  spines  along  the  inner 
edge  of  the  adambulacrals.  In  Mesopalseaster  the  ventral  spines  are 
better  developed,  fully  so  in  Promopalseaster,  and  probably  equally  so 
in  most  post-Ordovicic  forms. 

Among  the  primitive  cryptozonian  genera  Stenaster  and  Tetraster 
no  spines  are  now  seen,  but  undoubtedly  such  were  present  on  the 
actinal  side.  In  Ur  aster  ella  the  entire  dorsal  skeleton  is  more  or  less 
spinose,  consisting  of  long,  nonarticulating,  slender  rods,  the  dorsal 
extensions  of  the  ossicles.  In  the  multi-rayed  Cryptozonia  of  the 
Devonic,  spinosity  is  at  its  greatest  development  in  the  Paleozoic. 

Ambulacralia. — Undoubtedly  the  most  important  skeletal  parts  of 
the  Stelleroidea  are  the  ambulacrals.  In  general  they  undergo  the 
least  alteration  during  geologic  time  of  the  entire  asterid  skeleton, 
and  therefore  any  marked  variation  must  be  of  broad  classificatory 
value.  Schondorf  *  is  well  aware  of  this  fundamental  value  and  has 
made  full  use  of  it  in  denning  his  three  " classes,57  Asteroidea,  Aulu- 
roidea,  and  Ophiuroidea.  In  the  Asteroidea  the  ambulacralia  of  ad- 
joining columns  are  nearly  always  placed  directly  opposite  one 
another,  with  the  podia  issuing  through  openings  that  are  not  in  the 
plates  themselves,  but  laterally  between  two  adjoining  ambulacrals 
and  the  corresponding  adambulacrals.  Among  the  Paleozoic  asterids 
one  is  not  always  certain  whether  the  ambulacralia  are  arranged 
lt opposite"  or  "alternate,"  because  the  specimens  in  nearly  all  cases 
have  suffered  more  or  less  from  distortion.  In  many  good  specimens 
they  are  very  slightly  alternate,  but  in  all  such  cases  the  arrange- 
ment is  said  to  be  alternate.  In  other  fine  fossils  they  are  now 
alternate,  but  a  close  study  seems  to  show  that  originally  they  were 
practically  opposite  in  arrangement.  On  the  other  hand,  certain  of 
the  species  with  wide  ambulacral  furrows  and  large  ambulacralia,  as 
in  Promopalseaster,  Anorthaster,  and  Urasterella,  have  an  alternate 
arrangement,  while  in  other  species  of  the  first  and  last  named  genera 
they  are  just  as  certainly  opposite.  The  writer  therefore  does  not 

i  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63, 1910,  pp.  206-256;  Palaeontographica,  vol.  57, 1910, 
pp.  1-56. 


42  BULLETIN   88,  UNITED  STATES   NATIONAL  MUSEUM. 

lay  much  stress  upon  this  feature  among  the  Ordovicic  asterids,  nor 
does  he  regard  it  even  necessarily  as  of  specific  value,  but  in  the  later 
Asteroidea  the  arrangement  is  always  opposite  or  nearly  so.  Ver- 
rill  (1914:20)  states  that  he  has  noticed  the  alternate  arrangement 
in  living  Pycnopodia  "as  an  abnormal  variation  in  some  of  the 
rays,  and  also  that  it  may  occur  from  lateral  bending."  Evi- 
dently the  alternate  disposition  is  a  fixed  character  among  some 
Ordovicic  forms,  as  in  AnortJiaster,  but  more  will  certainly  be  dis- 
covered in  these  old  strata  and  probably  rather  among  the  Crypto- 
zonia  than  the  Phanerozonia.  The  writer  is  led  to  this  view  because 
of  the  alternate  arrangement  in  many  Auluroidea,  a  subclass  of 
Stelleroidea  that  seems  to  have  had  its  origin  in  some  cryptozoniaii 
asterid.  Out  of  the  Auluroidea  with  opposite  ambulacralia  came  the 
Ophiuroidea  with  their  highly  modified  ambulacrals  which  are 
coossified  into  "  vertebral  ossicles."  In  the  Auluroidea  the  arrange- 
ment of  the  ambulacrals  is  either  alternate  or  opposite,  but  they  are 
never  coossified  but  are  so  modified  as  to  suggest  the  Ophiuroidea 
rather  than  the  Asteroidea.  The  structure  of  these  plates  is  de- 
scribed elsewhere  and  need  not  be  repeated  here. 

The  ambulacrals  are  very  variable  in  number  throughout  the 
genera.  In  Hudsonaster,  Stenaster,  and  Tetr aster  there  are  as  few  as 
10  in  a  column,  while  in  Promopals&aster  there  are  certainly  50  and 
possibly  as  many  as  60.  The  cryptozonian  genus  Urasterella  has 
certainly  over  100  in  a  column.  In  general,  these  ossicles  abut 
against  each  other,  but  in  Urasterella  and  other  genera  they  overlap 
proximally  to  a  certain  extent.  As  yet  the  writer  has  seen  no 
Paleozoic  asterid  with  more  than  2  columns  of  ambulacrals,  though 
in  Promopalseaster  magnificus  the  proximal  areas  of  the  rays  for  a 
short  distance  have  4  columns  of  podial  openings.  Here,  however, 
the  ossicles  have  not  yet  wedged  themselves  into  4  columns  of 
ambulacralia. 

In  shape  and  surface  contour  there  is  also  considerable  variation 
among  the  ambulacralia.  In  Hudsonaster,  Tetraster,  and  several 
Devonic  genera  they  are  more  or  less  rectangular,  either  squarish  or 
drawn  out  laterally.  In  other  forms  of  Hudsonaster,  along  with 
Stenaster  and  Urasterella,  the  ossicles  are  h-  -shaped,  with  the  lateral 
shaft  thin,  thus  allowing  for  large,  elongate  podial  openings.  The 
more  primitive  genera  have  the  outer  surfaces  plain  or  slightly  ridged, 
while  in  derived  forms  like  Promopalseaster  the  ridges  are  high  and 
straight  or  have  their  medial  terminations  orally  directed.  In 
P.  magnificus,  the  ridges  in  the  proximal  region  are  arranged  in  pairs 
having  the  shape  of  a  tuning  fork;  in  P.  wyleqffi  one  sees  that  these 
ridges  approach  one  another  in  pairs  transitional  to  their  transforma- 
tion into  the  tuning-fork  form. 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  43 

Adambulacralia. — Adambulacralia  are  present  in  all  Stelleroidea. 
They  are  best  and  typically  developed  in  the  Asteroidea,  more  or 
less  modified  in  the  Auluroidea,  and  completely  altered  into  the  thin 
scalelike  side  plates  of  the  Ophiuroidea.  In  number  and  relative 
size  they  vary  as  do  the  ambulacralia,  being  least  numerous  and 
largest  in  the  most  primitive  genera.  Originally  they  probably 
bore  no  spines  at  all,  the  plates  being  practically  smooth.  In  Hud- 
sonaster  and  most  Ordovicic  and  Siluric,  and  some  Devonic  genera, 
their  surfaces  are  granular  to  tubercular.  These  protuberances  in  the 
younger  genera  may  have  borne  small  spines,  but  long  before  these 
appeared  each  adambulacral  bore  two  or  more  stout  or  slender,  com- 
paratively long  spines  along  its  ambulacral  edge. 

In  most  of  the  Paleozoic  genera  there  are  in  each  column  as  many 
adambulacrals  as  there  are  ambulacrals,  and  both  series  are  as  a  rule 
arranged  opposite  one  another.  In  Anorfhaster,  however,  there  are 
fewer  and  therefore  larger  adambulacrals  than  ambulacrals,  and 
these  latter  ossicles  clearly  alternate  with  one  another. 

In  the  Phanerozonia  the  adambulacrals  never  margin  the  rays 
but  always  lie  inside  of  the  bordering  inframarginals.  In  the  Crypto- 
zonia,  however,  the  adambulacrals  margin  the  animals  and  here  the 
ossicles  are  usually  small,  though  at  times  they  are  relatively  large 
and  make  a  stout  outer  skeletal  frame  as  in  Stenaster,  Tetraster, 
and  Schcenaster  (?}  montanus.  The  same  is  true  in  Encrinaster 
of  the  Auluroidea. 

The  adambulacrals  in  probably  all  the  Paleozoic  Phanerozonia 
continue  into  the  oral  region  and  each  two  adjoining  columns  meet 
here  in  a  pair  of  modified,  elongate,  pointed  pieces,  the  most  promi- 
nent ossicles  of  the  oral  armature.  No  other  skeletal  parts  lie  in 
front  of  these  oral  ossicles  except  in  the  phanerozonian  Hudsonaster 
narrawayi  (pi.  1,  fig.  1)  and  in  the  young  of  the  cryptozonian 
Urasterella  ulrichi  (pi.  30,  fig.  7).  Both  are  primitive  forms  of 
their  respective  phyla  and  whether  these  five  pieces  or  tori  are  to 
be  interpreted  as  five  spines  or  whether  they  represent  five  primi- 
tive orals  is  not  yet  determinable. 

Inframarginalia. — In  the  great  majority  of  Paleozoic  Phanero- 
zonia the  inframarginals  alone  margin  the  animals,  and  only  in  a 
few  forms  (Spaniaster,  Miomaster,  RJienaster,  and  Neopalseaster) 
have  the  supramarginals  moved  outward  and  completely  covered 
the  inframarginals,  so  that  the  two  columns  together  equally  bound 
the  rays  and  disk.  That  condition  is  a  peculiarity  common  to  most 
Paleozoic  phanerozonians,  while  the  wholly  superposed  arrange- 
ment distinguishes  nearly  all  the  Mesozoic,  Cenozoic,  and  Recent 
genera  of  the  same  kind  of  Asteroidea. 

The  inframarginals  are  usually  the  most  conspicuous  ossicles  of 
the  Paleozoic  Phanerozonia,  and  this  is  especially  true  where  the 


44  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

skeleton  is  strong  and  devoid,  or  nearly  so,  of  accessory  ossicles. 
They  are  ponderous  in  Hudsonaster,  Palseaster,  Australaster,  Devon- 
aster,  Xenaster,  Trimeraster,  Petraster,  etc.  When  the  smaller 
accessory  plates  are  introduced,  the  inframarginals  also  reduce  in 
size;  this  development  is  best  seen  when  passing  from  the  heavily 
plated  Hudsonaster  to  the  more  abundantly  plated  Mesopalseaster 
and  finally  Promopalseaster.  The  next  step  in  this  phyletic  line 
would  be  pronounced  a  cryptozonian  because  the  infra-  and  supra- 
marginals  could  not  be  distinguished  from  the  abundance  of  acces- 
sory ossicles.  In  fact,  it  is  not  always  easy  to  make  out  the  various 
categories  of  plates  even  in  Promopalseaster,  and  here  one  must 
resort  at  times  to  a  study  of  the  tips  of  the  rays  where  the  seven  pri- 
mordial columns  are  not  yet  disturbed  by  the  introduction  of  accessory 
pieces. 

In  primitive  Hudsonaster,  where  the  inframarginals  are  compara- 
tively very  large,  there  are  only  half  as  many  of  these  ossicles  as 
there  are  of  adambulacrals,  but  in  the  great  majority  of  Paleozoic 
genera  of  Phanerozonia  this  marked  difference  tends  to  be  less 
decided  and  toward  equalization.  In  certain  phyla,  as,  for  instance, 
from  Hudsonaster  to  Mesopalseaster  and  Promopalseaster,  the  equal- 
ization has  gone  on  rapidly,  hi  fact,  in  but  a  short  part  of  Ordovicic 
time.  In  more  conservative  stocks,  as  from  Hudsonaster  to  Devonic 
Xenaster  and  Trimeraster,  the  equalization  is  far  slower,  as  is  seen 
in  the  following  figures:  Hudsonaster,  12  inframarginals  and  24 
adambulacrals;  Trimeraster,  14  and  23;  and  Xenaster,  20  and  32, 
respectively.  In  nearly  all  the  genera  these  columns  of  plates  alter- 
nate with  one  another.'  This  of  course  must  be  so  where  the  number 
of  ossicles  is  different  in  the  two  columns,  and  complete  alternation 
is  retained  even  in  certain  species  where  the  numbers  of  ossicles  are 
alike,  as  for  instance  in  Promopalseaster  spinulosus.  On  the  other 
hand,  in  Mesopalseaster  sJiafferi,  where  there  are  16  inframarginals 
and  18  adambulacrals,  the  plates  alternate  in  the  proximal  half  of 
the  ambulacra  and  are  opposite  one  another  distally.  A  study  of 
the  growing  ray  tips  shows  that  the  various  ossicles  all  appear 
practically  of  one  size  and  where  there  are  more  adambulacrals  than 
inframarginals,  the  former  are  crowded  orally.  The  latter  develop- 
ment appears  to  be  the  primitive  type  of  growth,  but  this  mode  is 
rapidly  changed  to  one  in  which  the  seven  columns  of  primordial 
ossicles  appear  in  cycles  or  rings.  This  type  of  growth  is  easily  made 
out  in  primitive  forms  such  as  Hudsonaster  and  Mesopalseaster,  and 
in  some  species  of  Promopalseaster.  However,  when  accessory  plates 
are  developed  in  abundance,  and  especially  in  forms  where  the  seven 
primordial  columns  of  plates  remain  of  one  size,  their  introduction 
in  cycles  can  only  be  made  out  in  very  young  individuals  or  at  the 


KE VISION    OF   PALEOZOIC   STELLEKOIDEA.  45 

extreme  tips  of  the  rays,  conditions  not  often  attained  among  these 
fossils. 

In  the  great  majority  of  Paleozoic  Phanerozonia  the  inframar- 
ginals  and  adambulacrals  lie  closely  adjacent  to  one  another.  In 
typical  asterids  they  are  not  separated  by  the  introduction  of  acces- 
sory interbrachial  pieces  until  in  the  Devonic.  Here  in  Xenaster 
and  Trimeraster  isolated  pieces,  and  finally  a  column  of  them,  are 
inserted  in  the  proximal  half  of  the  rays.  In  the  large-disked  asterids, 
this  separation  occurs  much  earlier,  in  the  Middle  Ordovicic  in 
Petraster. 

In  Paleozoic  Phanerozonia  where  the  skeleton  is  made  up  of  an 
abundance  of  more  or  less  equal-sized  ossicles,  one  notices  also  on 
the  distal  portions  of  the  rays  a  tendency  for  the  inframarginals  to 
appear  on  the  dorsal  side  and  not  to  remain  on  the  ventral,  as  in 
primitive  stocks.  This  alteration  brings  the  adambulacrals  to  the 
margin  of  the  rays,  and  is  a  hint  as  to  how  Phanerozonia  gradually 
change  into  Cryptozonia.  It  is  best  seen  in  Promopalseaster,  Petras- 
ter, and  Mesopalxaster.  In  Australaster  it  is  a  marked  feature,  in 
fact,  one  can  say  that  the  distal  parts  of  the  rays  in  that  genus  are 
cryptozonian  while  the  bulk  of  the  arms  are  still  phanerozonian. 
This  ontogenetic  appearance  is  in  harmony  with  phylogenetic  devel- 
opment and  chronogenesis.  The  living  Echinaster  sepositus  is  in 
youth  also  a  phanerozonian,  but  at  maturity  is  a  typical  cryptozo- 
nian. In  so  typical  a  cryptozonian  as  Ur aster ella,  one  still  finds  in 
half -grown  U.  ulrichi  a  number  of  inframarginals  in  the  interradial  or 
axillary  areas.  The  same  retention  of  the  first  formed  inframargin- 
als is  also  met  with  among  the  multi-rayed  Cryptozonia  in  Helianih- 
aster,  and  even  among  the  Auluroidea  in  Encrinaster. 

It  has  just  been  pointed  out  how  the  inframarginal  columns  are 
eliminated  as  marginal  plates.  They  are  not,  however,  removed 
from  the  skeleton  in  these  early  forms  by  resorption  or  by  failure 
of  development,  but  for  want  of  special  growth.  In  other  words, 
the  inframarginals  are  probably  present  in  all  Paleozoic  Asteroidea, 
but  because  of  lack  of  specialization  through  the  developmental 
tendency  to  greater  skeletal  flexibility,  remain  small  and  are  lost 
as  such  in  the  mass  of  the  dorsal  plates.  This  apparent  eh'mination 
of  the  inframarginals  has  gone  on  independently  in  various  stocks 
as  pointed  out  elsewhere,  and  therefore  the  absence  of  large  marginals, 
either  infra-  or  supramarginals,  or  both  series,  is  not  of  ordinal  value. 

Supramarginalia. — In  Hudsonaster  the  prominent  supramarginal 
plates  of  the  dorsal  side  are  placed  decidedly  inside  of  the  inframar- 
ginals, though  the  former  clearly  overlap  the  latter.  This  primitive 
position  is  retained  in  many  Paleozoic  genera,  and  apparently  not 
before  the  Devonic  do  these  two  columns  of  ossicles  come  to  lie 
wholly  upon  one  another,  and  then  they  together  margin  the  animals. 


46  BULLETIN   88,  UNITED  STATES  NATIONAL  MUSEUM. 

It  is  apparently  always  a  rare  condition  in  the  Paleozoic,  but  as  the 
post-Devonic  asterids  are  as  yet  little  known,  we  can  more  accurately 
say  that  the  modern  type  of  Phanerozonia  is  unknown  before  Devonic 
tune.  It  should  be  added  here  that  complete  superposition  of  the 
supra-  upon  the  inframarginalia  undoubtedly  took  place  in  more 
than  one  stock  and  at  different  times.  Accordingly,  to  group  all 
asterids  with  large  marginalia  into  the  " order"  Phanerozonia  is 
further  proof  that  these  terms  cannot  be  used  in  the  phyletic  sense. 
Phanerozonia  and  Cryptozonia  are,  however,  of  use  in  a  descriptive 
way. 

The  supramarginals,  and  the  inframarginals  as  well,  in  primitive 
forms  gradually  attain  larger  size  down  the  columns  from  the  tips 
of  the  rays  toward  the  disk  and  mouth.  In  other  words,  the  older 
the  ossicle  in  primitive  genera,  the  larger  is  its  size,  and  in  all  such 
forms  the  pairs  of  supra-  and  inframarginal  columns  terminate  in 
single  plates,  the  primary  or  basal  supramarginals  and  the  primary 
or  basal  inframarginals.  The  latter  ossicles  in  the  most  primitive 
genera  are  situated  in  the  axils  of  the  rays  and  are  therefore  also 
known  as  axillary  marginals,  and  in  the  more  specialized  genera  the 
axillaries  and  even  pairs  of  inframarginals  are  crowded  orally  into 
the  interbrachial  areas.  The  basal  supramarginals  in  primitive 
forms  always  occur  prominently  on  the  disk,  in  derived  genera  they 
are,  however,  less  conspicuous,  and  where  the  disk  skeleton  is  made 
up  of  small  ossicles,  they  are  generally  indistinguishable  in  the  mass 
of  plates. 

We  have  seen  that  accessory  interbrachial  plates  in  some  genera 
are  developed  between  the  inframarginals  and  adambulacrals,  and 
to  a  greater  extent  the  same  is  true  of  the  development  of  ambital 
accessory  pieces  between  the  former  columns  and  the  supramarginals. 
In  probably  all  cases  where  the  rays  and  disk  grow  wider  the  addi- 
tional space  is  largely  covered  in  by  the  development  of  accessory 
plates.  As  it  is  in  the  disk  area,  and  therefore  necessarily  in  the 
basal  portion  of  the  rays  as  well,  that  the  main  increase  of  body 
extent  takes  place,  here  are  developed  the  greatest  number  of  these 
pieces.  Rarely  are  the  ambital  accessory  pieces  crowded  in  between 
these  columns  beyond  the  proximal  third  of  the  rays.  This  is  best 
seen  in  Devonaster  and  Xenaster,  but  in  the  large-disked  forms,  as 
Petraster,  they  extend  farther  out  and  are  present  to  within  the 
outer  third  of  the  rays.  Ambital  accessory  plates  may  also  be 
present  in  Mesopal&aster,  but  are  more  definitely  so  in  Promopalse- 
aster  (especially  in  P.  magnificus) ,  and  in  both  genera  they  occur 
throughout  the  greater  part  of  the  rays. 

Radialia. — In  many  Paleozoic  genera  of  Phanerozonia  and  even 
among  some  of  the  Cryptozonia,  a  more  or  less  prominent  column  of 
ossicles  is  seen  down  the  center  of  the  dorsal  side  of  the  arms.  These 


REVISION   OF  PALEOZOIC   STELLEEOIDEA.  47 

are  the  radial  columns  of  ossicles,  which  are  especially  well  seen  in 
Hudsonaster,  Spaniaster,  Devonaster,  Xenaster,  CaUiasterella,  and 
less  prominently  in  Mesopalseaster,  Promopalseaster,  and  Petraster. 
The  prominence  of  the  radials  is  lost  in  the  same  way  as  has  been 
described  for  similar  reduction  in  the  supramarginals  and  inframar- 
ginals. 

In  primitive  genera  the  supramarginals  and  radials  lie  closely 
adjacent  as  prominent  columns,  but  in  the  great  majority  of  Paleo- 
zoic Asteroidea  these  columns  are  more  or  less  extensively  separated 
from  one  another  by  the  introduction  of  radial  accessory  plates.  The 
latter  are  always  small  pieces  and  in  general  one  can  say  that  their 
number  increases  with  geologic  time  and  with  the  evolutionary 
complexity  of  the  various  stocks.  At  first  the  accessory  pieces  appear 
singly  between  the  plates  in  the  proximal  region  of  the  rays,  where, 
increasing  in  numbers,  they  separate  the  primary  columns  more  and 
more  and  finally  also  crowd  in  between  the  individual  ossicles,  es- 
pecially the  proximal  radials,  pushing  these  apart  more  or  less  com- 
pletely. This  is  true  not  only  in  chronogenesis  but  also  in  onto- 
genesis. It  is  best  seen  in  a  study  of  the  dorsal  areas  beginning  with 
Hudsonaster  and  Spaniaster,  and  proceeding  to  Mesopalseaster, 
Devonaster,  Promopalseaster,  and  Urasterella.  In  the  forms  with 
great  disks  the  development  of  accessory  plates  is  extreme,  as  may  be 
seen  in  Petraster  speciosus. 

The  columns  of  radial  plates  are  less  persistent  in  development 
than  any  other  of  the  primary  columns.  Like  all  of  the  primary 
plates,  the  radials  are  apt  to  lose  their  ponderosity  and  in  the  course 
of  geologic  time  become  smaller.  In  this  way  they  may  lose  their 
individuality  in  the  mass  of  dorsal  plaies,  but  in  some  cases  radialia 
appear  to  fail  to  develop  throughout  the  greater  part  of  the  rays, 
although  one  or  more  primordial  ossicles  of  each  radius  are  present 
on  the  disk.  In  certain  species  of  Mesopalseaster,  and  more  especially 
in  Promopalseaster,  the  radialia  are  either  not  present  or  have  been 
squeezed  out  of  the  mid  line  of  each  radius  so  as  to  be  unrecognizable. 
In  other  forms  of  the  latter  genus  they  are  well  developed  and  arranged 
in  linear  columns.  Promopalseaster  as  a  rule  has  no  radialia  on  the 
rays  and  the  space  between  the  supramarginals  is  occupied  by  many 
small  accessory  radial  pieces.  Among  the  Cryptozonia,  radialia  are 
usually  not  discernible  as  such  on  the  rays,  though  present  on  the  disk. 

Accessory  plates. — These  small  pieces  of  irregular  form  are  space 
fillers  between  all  of  the  primary  columns  of  plates,  with  the  exception 
of  the  ambulacrals  and  adambulacrals.  As  the  body  cavity  grows 
larger,  skeletal  increase  takes  place  either  through  enlargement  of 
the  seven  primordial  columns  of  ossicles  or  by  the  intercalation  and 
formation  of  new  pieces,  the  accessory  plates.  The  former  method 

50601°— Bull.  88—15 4 


48  BULLETIN 

is  the  one  least  often  resorted  to.  The  accessory  pieces  appear  first 
chronogenetically  on  the  disk,  separating  the  primordial  ossicles 
one  from  another  in  various  ways,  and  as  the  body  cavity  grows 
larger  in  the  course  of  geologic  time,  they  wedge  all  of  the  primary 
columns  apart  proximally  except  the  ambulacrals,  which  compensate 
for  the  widening  of  the  rays  by  growing  in  size  transversely.  Some 
accessory  plates  also  develop  in  the  interbrachial  areas  separating 
the  interbrachial  marginals,  as  in  Trimeraster  and  Xenaster,  while 
in  the  large-disked  forms,  as  Petraster,  their  number  becomes  excessive. 

Ocular  plates. — The  large  ocular  plates  seen  in  so  many  living 
Phanerozonia  are  very  rarely  developed  in  Paleozoic  forms.  In 
fact,  the  writer  knows  of  but  a  single  occurrence,  in  the  Lower  Car- 
boniferous genus  Neopalseaster. 

It  seems  to  the  author  that  these  ossicles  should  have  considerable 
significance  in  phylogeny  because  their  large  growth  indicates  that 
they  are  much  older  plates  than  any  of  the  small  adjacent  pieces. 
In  other  words,  in  all  genera  where  the  ocular  or  sensory  tentacle 
does  not  lie  in  an  enlarged  and  grooved  plate,  the  newly  developed 
ossicles  of  either  the  ventral  or  dorsal  side  appear  distally  to  the  pre- 
viously borne  pieces,  i.  e.,  at  the  tips  of  the  rays,  whereas  in  the  stocks 
having  ocular  plates  the  new  skeletal  arrivals  appear  not  at  the  tips 
of  the  rays  but  on  the  proximal  side  or  inside  of  the  eye  ossicles 
Therefore,  where  ocular  plates  are  present,  these  pieces  are  not  only 
enlarged  in  size  with  age,  but  progressively  pushed  farther  and  farther 
outward  as  well  by  the  growing  ray  tips  that  lie  on  their  inner  sides. 
This  mode  of  growth  may  have  originated  once  or  several  times, 
there  being  in  the  latter  case  parallel  developments  of  ocular  plates. 
This  is  a  study  that  can  not  be  pursued  far  among  Paleozoic  genera, 
but  in  the  later  forms  may  be  productive  in  the  discerning  of 
phylogenetic  lines. 

After  the  above  was  written  the  writer  read  in  Verrill  (1914:  20-22) 
that  Fewkes  has  shown  the  ocular  plates  to  be  the  first  to  appear  in 
the  young,  and  that  with  growth  they  are  pushed  distaUy  because 
of  "the  budding  in  of  new  plates  between  the  apical  plate  and  the 
one  next  to  it.7'  These  observations  on  living  starfishes  are  therefore 
in  harmony  with  the  study  of  Neopalseaster,  and  go  to  show  that  the 
bulk  of  Paleozoic  starfishes  insert  the  plates  of  the  primary  columns 
in  a  different  way,  i.  e.,  always  distally.  On  this  ground  alone  most 
of  the  Paleozoic  starfishes  should  be  grouped  by  themselves  and 
apart  from  most  of  the  subsequent  Phanerozonia. 

Centro-dorsal. — In  the  center  of  the  disk  of  many  Paleozoic  genera 
of  Asteroidea  and  of  some  Auluroidea  is  seen  a  more  or  less  prominent 
plate,  which  is  thought  to  be  the  equivalent  of  the  centro-dorsal  of 
the  embryo  of  the  living  crinid  Antedon  (Comatula).  It  is  a  promi- 
nent though  small  plate  in  most  of  the  forms  of  Hudsonaster  and  in 


REVISION   OF  PALEOZOIC   STELLEEOIDEA.  49 

Palxaster;  it  is  also  well  developed  though  less  conspicuous  in  Meso- 
palseaster,  Spaniaster,  Xenaster,  Agalmaster,  Devonaster,  Neopalseaster, 
Palasterina,  Monaster,  CalliastereTla,  and  Urasterella. 

As  the  disk  plates  are  rarely  well  preserved,  and  as  the  centro- 
dorsal  has  been  seen  in  many  Paleozoic  species,  the  writer  thinks- 
it  will  be  found  in  most  of  the  forms  of  this  era. 

Primary  disk  plates. — In  the  most  primitive  and  oldest  Paleozoic 
asterids  the  centro-dorsal  is  surrounded  by  a  variable  but  small 
number  of  diminutive  accessory  disk  pieces.  In  mature  Hudsonaster 
they  form  a  single  ring,  but  in  the  young  of  the  cryptozonian  Uras- 
terella ( U.  ulrichi)  and  in  mature  CalliastereTla  there  are  none  of  these 
accessory  pieces  present.  For  these  reasons  it  is  thought  that  in 
the  Ordovicic  there  will  be  found  a  small  asterid,  even  more  primitive 
than  Hudsonaster,  that  will  be  devoid  of  accessory  disk  pieces. 

Around  the  centro-dorsal  of  young  Urasterella  and  in  mature 
Calliasterella,  there  follows  directly  a  ring  of  five  larger  plates.  The 
same  five  plates  are  also  seen  outside  of  the  single  ring  of  accessory 
pieces  in  Hudsonaster  and  Spaniaster,  and  directly  beyond  the  two 
rings  of  accessories  in  Mesopalseaster.  These  more  or  less  large 
plates  are  radial  in  position  and  are  the  basal  radialia  above  which 
continue  the  columns  of  successively  formed  radials. 

Keturning  to  Hudsonaster,  we  see  that  the  first  ring  of  prominent 
plates  has  10  pieces,  5  of  which  are  radial  in  position,  the  remainder 
interradial.  The  same  is  true  for  Spaniaster  and  Xenaster,  while 
Calliasterella  has  an  equal  number  of  plates  in  the  second  ring.  An 
analysis  of  these  disks  shows  that  5  of  the  plates  are  either  primary 
or  secondary  radialia,  while  the  remainder  are  situated  interradially, 
and  upon  them  rest  the  10  columns  of  supramarginals.  The  first 
prominent  ring  in  Mesopalseaster  sJi'Offeri  and  Devonaster  and  the 
second  ring  in  Urasterella  ulriclii  each  have  15  plates,  5  of  which 
are  radialia,  while  the  other  10  are  supramarginals.  Simplifying 
these  statements  and  cutting  out  the  accessory  pieces,  we  learn  that 
the  disks  of  these  genera — and  others  could  be  added — are  composed 
of  a  centro-dorsal,  a  first  ring  of  5  radialia,  and  a  second  one  with  5 
radialia  and  10  basal  supramarginaiia.  This,  then,  is  the  same  struc- 
ture postulated  for  the  hypothetic  phylembryo  of  Asteroidea  and 
deduced  through  reduction  of  ossicles,  as  gleaned  from  a  partial 
ontogenesis  of  Hudsonaster. 

Axillary  ossicles. — In  the  most  primitive  asterid,  Hudsonaster,  one 
sees  in  each  axilla  a  single  large  plate,  on  either  side  of  which  adjoin 
the  10  columns  of  inframarginals.  The  same  arrangement  obtains 
in  Siluraster,  Palseaster,  and  Australaster  (here  the  genus  occurs  in  the 
Permo-Carboniferous,  and  the  axillaries  are  very  large  contrasting 
with  the  smaller  ones  of  the  Ordovicic  Hudsonaster).  In  no  other 
Paleozoic  genera  does  this  same  development  hold,  though  the  single 


50  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

axillaries  occur  in  many  other  forms  where  they  are,  however,  pushed 
orally  into  the  skeleton  of  the  interbrachial  areas.  Single,  not  double, 
axillaries,  therefore,  make  the  simplest  and  smallest  type  of  inter- 
brachial areas.  Further  complexity  and  enlargement  of  these  areas 
are  produced  by  crowding  into  them  orally,  first  the  axillaries  and 
then  one  or  more  pairs  of  proximal  inframarginals. 

In  Hudsonaster  narrawayi  one  sees  tiny  single  plates  proximal  to 
each  axillary.  These  are  clearly  of  no  marked  morphologic  value  and 
are  to  be  interpreted  as  accessory  plates.  Similar  single  ossicles  are 
also  seen  in  genera  with  large  interbrachial  areas,  as  in  Promopalseaster. 
They  are  regarded  as  space-fillers  and  without  ancestral  significance. 

Interbrachial  areas. — The  simplest  type  of  interbrachial  area  is  that 
just  described.  Increase  in  size  and  complexity  of  interbrachial  struc- 
ture is  a  natural  result  from  an  enlarged  body  cavity.  The  first  change 
in  this  direction  is  seen  in  Mesopaldeaster,  Spaniaster,  Miomaster,  and 
Devonaster,  where  the  axillaries  are  crowded  orally  and  surrounded 
distally  by  a  pair  of  adjoining  basal  inframarginals,  and  proximally  by 
a  variable  number  of  adambulacrals.  The  same  development  is  seen 
but  hi  somewhat  modified  form  in  the  cryptozonian  genera  Urasterella 
(U.  ulrichi  and  U.  girvanensis)  and  CaUiasterella.  Here  the  axillaries 
are  present  only  in  the  young,  but  may  be  retained  to  maturity;  in 
either  case  they  may  or  may  not  be  margined  distally  by  basal  infra- 
marginals.  As  the  inframarginals  in  these  forms  are  vanishing  (pri- 
mitive Cryptozonia),  we  should  expect  to  find  related  genera  devoid 
of  even  the  axillaries,  and  such  is  the  case  in  Stenaster  and  Tetraster. 

The  next  step  in  the  enlargement  of  the  interbrachial  areas  consists 
of  the  inward  crowding  of  pairs  of  basal  inframarginals,  one  or  more 
at  a  time.  In  Trimeraster  these  areas  have  the  single  axillaries  and  a 
pair  of  basal  inframarginals,  with  the  second  pair  of  proximal  infra- 
marginals  making  the  margin  of  the  axils.  In  Xenaster  the  first  and 
second  pairs  of  proximal  inframarginals  are  enclosed,  while  in  Pro- 
mopalseaster  there  are  from  one  to  three  pairs  in  each  interbrachial 
area.  As  these  areas  enlarge,  it  follows  that  more  and  more  of  the 
adambulacrals  must  also  take  part  in  the  expansion.  These  ossicles 
are  therefore  called  interbrachial  adambulacrals.  Further  enlarge- 
ment, but  not  to  any  marked  extent,  takes  place  through  the  insertion 
of  a  variable  number  of  accessory  disk  interbrachials.  This  is  best 
seen  in  Trimeraster  and  Xenaster. 

Abnormal  enlargement,  but  to  a  small  extent,  of  the  interbrachial 
areas  takes  place  through  oral  crowding  entirely  of  adambulacrals  in 
pairs  and  through  the  increase  in  size  of  some  of  these  ossicles.  This 
type  of  development  is  known  only  in  Anorthaster. 

It  has  been  shown  how  enlargement  of  the  interbrachial  areas  comes 
about  through  oral  crowding  of  the  axillaries,  proximal  inframargi- 
nals  and  adambulacrals — pieces  of  the  primary  skeleton — but  the 


REVISION   OP  PALEOZOIC   STELLEROIDEA.  51 

greatest  expansion  is  brought  about  by  the  introduction  of  more  and 
more  accessory  disk  pieces  between  the  adambulacrals  and  inframar- 
ginals.  The  beginning  of  this  development  of  the  secondary  skeleton 
is  seen  in  Petr aster  and  is  variously  progressive  in  the  different  species. 
They  finally  crowd  more  and  more  distally  into  the  rays,  as  may  be 
seen  in  Uranaster  and  Palseostella.  Among  the  large-disked  Crypto- 
zonia,  as  Schuchertia  and  the  Palasteriscidse,  it  is  the  ambital  and 
abactinal  accessory  pieces  that  go  to  enlarge  the  arcs  and  body  cavity. 

CLASSIFICATION. 

A  good  history  of  the  various  attempts  at  classifying  the  fossil 
starfishes  is  given  by  Spencer  (1914: 39-52).  How  recent  starfishes 
are  classified  may  be  learned  from  Verrill  (1914:24),  and  it  will  be 
seen  that  his  principles  are  not  always  applicable  to  fossil  forms  be- 
cause of  the  loss  of  parts  through  fossilization.  In  subsequent  pages 
the  author  will  give  his  groupings  up  to  superfamilies,  but  the  time 
is  not  yet  at  hand  for  an  ordinal  classification  applicable  alike  to 
fossil  and  recent  starfishes. 

Catalogue  of  Paleozoic  Stelleroidea. — A  catalogue  of  all  Paleozoic 
starfishes  was  published  by  the  writer  in  April,  1914,  under  the  title 
"Fossilium  Catalogus,  Anirnalia,  part  3,  Stelleroidea  palseozoica,"  pp. 
53  (Junk,  Berlin).  It  gives  the  entire  bibliography  of  the  genera  and 
species  up  to  that  date,  and  an  outline  of  the  classification  adopted. 
The  actual  date  of  several  new  genera  is  of  the  work  above  cited, 
although  they  are  also  printed  in  the  present  book  as  new.  This 
Bulletin  is  there  cited  as  of  1914  and  is  now  to  be  corrected  to  1915. 
The  above-mentioned  catalogue  will  always  be  useful  for  ready  refer- 
ence to  the  literature,  although  the  larger  volume  repeats  all  of  the 
essential  references,  corrected  to  November,  1914. 

DESCRIPTION  OF  GENERA  AND  SPECIES. 

Class  STELLEROIDEA. 

Subclass  ASTEROIDEA. 

PHANEROZONIA  Sladen. 

Asteroidea  nearly  always  with  large  marginal  plates.  These  consist 
in  the  Mesozoic  and  later  asterids  Qf  completely  superposed  inframar- 
ginals  and  supramarginals;  in  the  Paleozoic  the  rule  is  that  the  in- 
framarginals  alone  border  the  animal,  while  the  supramarginals  are 
always  dorsal,  generally  alternate  with  the  inframarginals,  and  are 
placed  farther  inward  though  resting  more  or  less  upon  the  latter. 

Ambulacrals  always  present  and  opposite  in  arrangement  in  post- 
Paleozoic  forms.  In  the  oldest  and  most  primitive  Paleozoic  forms 
they  are  apt  to  be  alternate  throughout  the  rays,  or  only  so  distally 
in  the  young  parts.  By  far  the  greater  number  of  Paleozoic  forms, 
however,  have  the  opposite  arrangement. 


52  BULLETIN   88,  UNITED  STATES  NATIONAL  MUSEUM. 

Oral  armature  always  with  the  adambulacral  pieces  most  con- 
spicuous. 

This  order  is  not  known  to  appear  before  the  Middle  Ordovicic, 
and  in  the  Paleozoic  contains  the  following  families: 

Hudsonasteridae.  Xenasteridae. 

Palaeasteridae.  Neopalaeasteridae. 

Promopalaeasteridae.  Palasterinidae. 

Mesopalaeasterinae.  Lepidasteridae. 

Promopalaeasterinae. 
Anorthasterinae. 

These  seven  families  of  Paleozoic  asterids  are  all  related  to  one 
another  and  seemingly  had  their  origin  more  or  less  directly  in 
Hudsonaster  or  a  form  very  similar  to  it.  Therefore  the  family 
Hudsonasteridae  is  the  primordial  stock  out  of  which  all  asterids 
progressively  developed.  Hudsonaster  is  massively  and  simply 
built,  with  the  spines  rudimentary  and  restricted  to  the  adambula- 
crals  and  inf ramarginals ;  it  is  a  small  rigid  asterid  with  few  and 
comparatively  large  ossicles,  nearly  all  of  which  are  of  the  pri- 
mary skeleton.  From  it  the  evolutionary  tendency  was  to  get  rid 
of  the  rigidity  and  ponderosity  through  the  comparative  reduction 
in  size  of  the  plates  and  the  introduction  of  many  smaller  sec- 
ondary pieces,  along  with  an  abundance  of  spines.  With  this  ten- 
dency once  established,  there  arose  several  others:  (1)  elongation 
of  rays,  with  greater  flexibility  and  greater  power  of  locomotion 
through  the  indefinite  duplication  of  pairs  of  podia;  (2)  increase  of 
body  cavity  in  three  different  ways.  This  took  place  through  the 
development  of  interbrachial  areas  (a)  by  the  inward  crowding  of 
the  single  interbrachial  axillaries,  followed  by  more  and  more  pairs 
of  proximal  inf  ramarginals;  (&)  through  the  insertion  of  an  indefinite 
number  of  accessory  ossicles  between  the  adambulacrals  and  the 
inf  ramarginals,  forcing  the  latter  more  and  more  outward;  and 
(c)  through  the  introduction  of  supernumerary  rays.  The  latter 
development  is  probably  abnormal,  in  that  the  tendency  arose  in 
the  later  larval  life  as  is  explained  elsewhere.  (See  p.  207.)  With 
these  changes  of  the  actinal  side  naturally  must  arise  compensating 
growths  of  the  abactinal  surface  and  accordingly  here  is  seen  the 
introduction  of  accessory  ossicles  in  various  places. 

Starting  with  Hudsonaster,  there  is  one  phyletic  line  developed 
through  the  elongation  of  rays,  flexibility,  and  the  increase  in  size 
of  the  oral  region  by  the  (a)  method  from  the  primitive  Hudson- 
asteridae into  the  derived  Palaeasteridae,  Promopalaeasteridae,  Xen- 
asteridae,  and  Neopalaeasteridae.  This  is  the  most  satisfactory  line 
of  evolution,  resulting  in  the  greatest  variety  of  genera.  Again 
with  Hudsonaster  as  the  radicle,  another  phyletic  line  is  established 
through  the  increase  of  the  body  cavity  by  the  (6)  method,  giving 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  53 

rise  to  the  Palasterinidse.  This  line  of  change  is  not  at  all  so  pro- 
ductive of  genera  as  the  former.  Finally,  a  third  phyletic  line  is 
established  through  larval  adaptation,  causing  a  sixth  ray  to  develop 
and  thereafter  pairs  of  rays,  resulting  in  the  multi-rayed  asterids  of 
the  family  Lepidasteridae. 
These  phyletic  lines  may  be  expressed  taxonomically  as  follows: 

Superfamily  Promopalseasteracea,  new. 

Includes    families    Hudsonasteridae,    Palseasteridse,    Promopalseasteridae,    and 
Xenasteridae.    The  Neopalseasteridae  developed  out  of  the  Promopalaaasteridse. 
Superfamily  Palasterinacea,  new. 

Includes  family  Palasterinidse. 
Superfamily  Lepidasteracea,  new. 

Includes  family  Lepidasteridse. 

HUDSONASTERID.E,  new  family. 

Most  primitive  known  Phanerozonia. 

Small,  five-rayed,  heavily  plated  asterids,  with  narrow  ambulacral 
furrows  and  slightly  alternate  ambulacralia.  The  incipient  inter- 
brachial  arcs  are  occupied  by  single  axillary  marginal  plates.  Abac- 
tin  ally  the  rays  have  five  columns  of  ossicles,  the  radials  in  the  center 
being  bounded  on  either  side  by  the  supramarginals  and  inframarginals; 
the  latter  margin  the  rays  and  the  ossicles  of  adjoining  columns  alter- 
nate with  one  another.  There  are  no  accessory  ray  plates  of  any 
kind.  The  disk  has  a  prominent  central  disk  piece  separated  by  a 
small  number  of  accessory  disk  plates  from  a  ring  of  five  large  basal 
radials  and  five  large  basal  interradial  ossicles.  Spines  rudimentary 
and  apparently  restricted  to  the  adambulacrals  and  inframarginals. 

This  family  contains  the  genera  Hudsonaster  Stiirtz  and  Siluraster 
Jaekel. 

Genus  HUDSONASTER  Sturtz. 

Plates  1-6. 

Palseaster  (part)  of  authors. 
Hudsonaster  STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.   56,    1900, 

pp.  224,  225. 
Protopalseaster  HUDSON,  Ottawa  Naturalist,  vol.  26,  1912,  p.  25;  vol.  27,  1913, 

pp.  77-84. — RAYMOND,  Ottawa  Naturalist,  vol.  26,  1912,  p.  105  (genoholo- 

type,  P.  narrawayi). — SPENCER,  Mon.  Brit.  Pal.  Asterozoa,  pt.  1  (Palaeontgr. 

Soc.  for  1913),  1914,  p.  21. 

The  name  is  derived  from  the  " Hudson  River  formation/7  an 
Ordovicic  series  of  strata  of  long  endurance.  If  the  stratigraphic 
term  is  used  correctly,  then  these  rocks  have  as  yet  furnished  no 
starfishes  of  this  genus;  for  this  reason  Hudsonaster  is  a  misnomer 
and  has  no  significance,  but  under  the  rules  of  nomenclature  it  must 
be  accepted. 

Generic  characters. — Disk  small  and  without  actual  interbrachial 
arcs.  Rays  five,  short,  tapering  rapidly. 


54  BULLETIN   88,  UNITED  STATES   NATIONAL  MUSEUM. 

Abactinal  area  of  rays  occupied  by  three  columns  of  large,  thick, 
more  or  less  tumid  or  carinate,  closely  adjoining,  tuberculate  plates; 
more  or  less  of  the  inframarginal  plates  are  also  to  be  seen,  making 
five  visible  columns  of  plates  on  each  ray  abactinally.  There  is, 
therefore,  a  single  radial  column  bounded  on  each  side  by  two  columns 
of  supramarginal  and  two  of  inframarginal  plates.  The  latter 
columns  are  the  marginal  plates  both  actinally  and  abactinally,  but 
on  the  dorsal  side  are  overlapped  by  the  supramarginals.  In  the 
center  of  the  disk  there  is  a  small  but  very  tumid  plate  (central 
disk  plate)  around  which  is  a  nearly  complete  circle  of  smaller  acces- 
sory plates  and  an  open  space  which  may  represent  an  anal  opening. 
Outside  of  this  first  circle  of  accessory  plates  there  is  a  ring  of  10 
very  large  plates  that  in  the  geologically  later  species  are  stellate 
on  the  surface,  5  of  which  are  radial  and  5  interradial  in  position. 
The  radial  plates  are  the  basal  radial  plates  of  the  5  medial  columns, 
while  the  5  interradial  plates  give  rise  to  the  10  larger  and  conspicu- 
ous supramarginal  ossicles.  The  basal  supramarginals  adjoin  one 
another  in  the  axillary  areas,  and  in  the  geologically  later  forms 
these  also  have  stellate  surfaces.  Between  each  of  the  5  inter- 
radial plates  there  is  inserted  a  single  plate,  making  a  second  but 
disconnected  ring  of  accessory  plates. 

Madreporite  abactinal,  more  or  less  large,  adjoining  one  of  the 
large  interradial  plates  and  between  the  basal  plates  of  two  supra- 
marginal  columns  of  ossicles  of  adjoining  rays. 

No  accessory  ambital  or  abactinal  plates. 

Spines  appear  to  be  absent  everywhere  except  on  the  inframarginal 
and  adambulacral  ossicles.  Otherwise  the  surface  is  granular  or 
tuberculate. 

Inframarginal  plates  well-developed,  tuberculate,  and  common 
to  both  the  actinal  and  abactinal  areas.  These  proximally  adjoin  the 
five  isolated  and  large  axillary  marginals,  each  one  of  which  occupies 
.an  axil  of  the  rays.  Each  plate,  except  the  axillary  ones,  bears  on 
its  outer  edges  one  to  three  apparently  smooth,  small  spines. 

Axillary  plates  quite  conspicuous,  marginal,  and  one  in  each 
actinal  axil.  In  at  least  one  of  the  species  there  is  a  single  tiny  acces- 
sory piece  orad  to  each  axillary  (H.  narrawayi),  and  it  is  only  seen 
on  the  inside  of  the  skeleton. 

Adambulacral  plates  numerous,  one  or  two  to  each  inframarginal 
plate  and  two  on  each  side  of  each  axillary  marginal  plate.  All  of 
these  pieces  bear  at  least  two  spines,  one  on  the  inner  and  another 
on  the  outer  edges. 

Oral  armature  consisting  of  at  least  five  pairs  of  pointed  and  elon- 
gate basal  adambulacral  plates;  each  bears  spines  like  the  other 
ambulacrals.  In  rare  cases  issuing  from  beneath  these  ossicles  may 
be  seen  five  single  stout  spines  or  plates  (tori)  that  are  connected 


REVISION   OF  PALEOZOIC   STELLEKOIDEA.  55 

with  the  pairs  of  ambulacral  armature  pieces.  In  H.  narrawayi  above 
or  dorsal  to  the  pair  of  large  oral  pieces  there  is  another  but  smaller 
and  modified  pair  of  ambulacral  ossicles  clearly  also  a  part  of  the  oral 
armature. 

Ambulacral  grooves  originally  narrow  and  regularly  tapering.  Am- 
bulacral plates  rectangular,  practically  opposite  or  very  slightly 
alternating,  one  to  each  adambulacral  plate.  The  ambulacralia 
of  each  column  may  be  so  closely  adjoining  as  to  leave  almost  no 
space  for  the  podial  openings,  or  there  may  be  laterally  between 
adjoining  ossicles  very  large  openings. 

Genoholotype. — The  genotype  selected  by  Sttirtz  is  Pdlasterina 
rugosa  Billings.  The  above  generic  definition  is,  however,  largely 
based  upon  Palxaster  incomptus  Meek  and  P.  matutinus  Hall. 

Distribution. — Restricted  to  the  middle  and  upper  portion  of  the 
Ordovicic.  The  following  are  the  known  species : 

H.  matutinus  (Hall).     Trenton. 

H.  narrawayi  (Hudson).     Black  River. 

H.  milleri,  new  species.     Trenton. 

H.  incomptus  (Meek).     Maysvillian  and  Richmondian  series. 

H.  rugosus  (Billings).     Lower  Richmondian,  Charleton  forma- 
tion. 

H.  ~batheri,  new  species.  Upper  Ordovicic,  Girvan,  Scotland. 
Remarks. — Sttirtz  is  unfortunate  in  selecting  as  the  genotype  of 
Hudsonaster,  Palasterina  rugosa  Billings,  a  very  poorly  known  starfish 
from  the  Richmondian  of  Anticosti  Island.  Therefore  his  original 
definition  of  Hudsonaster  is  not  only  very  imperfect,  but  the  specimen 
is  wrongly  interpreted.  His  characterization  of  the  genus  is  as 
follows : 

Of  Palasterina  rugosa  only  the  abactinal  side  is  known.  On  the  disk  occur  orna- 
mented, deeply  crenulate,  star-shaped  plates.  Four  [the  specimen  is  distorted  and 
has  forced  into  view  one  of  the  inframarginal  columns,  while  the  one  on  the  other  side 
of  the  ray  is  shoved  out  of  sight]  regular  and  decided  columns  mark  the  rays,  and  of 
these  the  outer  rows  are  stronger  than  the  inner  columns.  The  outer  columns  consist 
of  unmistakable  marginal  plates  [one  is  inframarginal,  the  other  is  a  supramarginal 
column].  According  to  Billings  there  are  even  traces  of  the  actinal  marginals  to  be 
seen  from  the  abactinal  side.  Spines  absent  [the  usual  spines  of  this  genus  are  also 
present  here].  The  arms  terminate  sharply  in  points. 

Sttirtz  is  correct  in  saying  that  this  species  can  not  be  included  in 
Palasterina  and  also  that  the  genus  has  come  to  embrace  a  variety 
of  unrelated  genera.  However,  he  does  not  say  what  are  the 
actual  generic  characters  of  Hudsonaster,  but  as  P.  rugosa  is  not  a 
Palasterina  he  concludes  that  as  "new  generic  names  are  required 
I  propose  Hudsonaster  for  Palasterina  rugosa  Billings. "  This 
species  is  undoubtedly  congeneric  with  Palseaster  incomptus,  a  form 
fully  described  in  this  work  both  from  the  actinal  and  abactinal  sides, 
and  is  therefore  taken  as  the  genotype  for  the  above  generic  defini- 
tion. 


56  BULLETIN   88,  UNITED  STATES   NATIONAL  MUSEUM. 

The  adopted  genotype  of  Protopalseaster  (P.  narrawayi)  is  described 
at  length  and  in  detail  by  Hudson,  but,  thinking  the  specimen 
showed  the  actinal  side,  he  described  the  ambulacrals  as  epineural 
plates  roofing  over  the  ambulacral  furrow,  a  character  that  he  of 
course  recognized  as  wholly  anomalous  for  starfishes.  Raymond 
later  on  showed  that  the  actinal  side  of  this  specimen  lies  buried  in 
the  rock  and  that  the  entire  abactinal  plates  are  now  gone,  so  that 
the  view  is  of  the  actinal  plates  from  their  inner  side,  i.  e.,  an  inter- 
nal view  of  the  ventral  skeleton  (later  Hudson  combats  this  view). 
Under  these  circumstances  nearly  all  of  Hudson's  generalizations 
are  fallacious  and  especially  his  statement  that  "we  are  dealing 
with  an  unrecognized  and  very  archaic  morphological  type  which 
links  the  Edrioasteroidea  with  the  Stelleroidea  "  (1912 :  24) .  A  proper 
interpretation  of  the  specimen  shows  it  to  be  a  primitive  but  other- 
wise a  normal  early  Paleozoic  starfish.  Even  though  Hudson's 
genus  is  far  better  determined  generically  than  that  of  Stiirtz,  it 
must  give  way  to  the  older  name  Hudsonaster.  No  one  regrets  this 
more  than  the  writer,  because  the  generic  name  Protopalseaster  ex- 
presses the  phyletic  relationship  of  these  primitive  starfishes  and  is  a 
name  that  he  has  had  in  manuscript  for  the  past  15  years. 

Hudsonaster  has  its  nearest  known  relationship  in  Palseaster,  but 
differs  at  once  from  the  latter  in  that  the  rays  have  abactinally  five 
columns  of  plates,  while  Palseaster  has  but  four.  In  other  words, 
Palseaster  has  no  radial  columns  of  ray  plates,  but  their  place  is  oc- 
cupied by  numerous  small  accessory  pieces.  The  abactinal  disk 
of  Palseaster  is  also  quite  different  hi  having  numerous  small  acces- 
sory ossicles,  while  in  Hudsonaster  this  area  is  devoid  of  these  pieces 
and  instead  there  are  disk  plates  that  are  larger,  far  less  numerous, 
and  with  a  definite  arrangement. 

The  plate  arrangement  of  Hudsonaster  is  simple  and  primitive 
in  that  it  distinctly  retains  to  maturity  much  of  the  larval  plate 
structure  of  recent  species  and  does  not  develop  accessory  ambital 
or  accessory  abactinal  plates  as  do  its  descendants  Mesopalseaster 
and  particularly  Promopalseaster.  In  Hudsonaster  the  axils  are 
occupied  by  single,  large,  axillary  marginals,  against  which  rest 
the  columns  of  inframarginal  plates  of  adjoining  rays.  In  the  other 
two  mentioned  genera,  interbrachial  arcs  begin  to  develop  by  crowd- 
ing orally  the  axillary  marginals,  when,  as  in  Mesopalseaster ,  the 
proximal  plates  of  the  inframarghial  series  of  adjoining  rays  abut 
against  each  other.  In  Promopalseaster  this  crowding  of  the  infra- 
marginal  plates  into  the  interbrachial  areas  is  continued,  always  a 
pair  of  plates  at  a  time  passing  orally.  For  other  remarks  on  the 
development  and  distinction  between  these  genera,  see  Mesopalse- 
aster  and  Promopalseaster. 


REVISION   OF  PALEOZOIC   STELLEKOIDEA.  57 

In  the  Lower  Carboniferous  genus  Neopalseaster  the  primitive 
disk  structure  of  Hudsonaster  is  also  retained  in  its  essential  fea- 
tures. Otherwise  these  genera  are  easily  distinguished,  as  is  pointed 
out  in  the  remarks  on  Neopalseaster. 

HUDSONASTER  MATUTINUS  (Hall). 
Plate  2,  fig.  2;  plate  3,  fig.  2;  plate  5,  figs.  1,  2. 

Asterias  matutina  HALL,  Nat.  Hist.  N.  Y.,  Pal.,  vol.  1,  1847,  p.  91,  pi.  29,  figs. 

5o,  56. 
Palxaster  matutinus  HALL,  Twentieth  Eep.  N.  Y.  State  Cab.  Nat.  Hist.,  1868, 

p.  283,  pi.  9,  fig.  2;  rev.  ed.,  1868=1870,  p.  325,  pi.  9,  fig.  2. 
Petraster  rigidus  (part)  BILLINGS,  Geol.  Surv.  Canada,  Can.  Org.  Bern.,  dec.  3, 

1858,  pi.  10,  fig.  36  (not  fig.  3a).— HALL,  Twentieth  Rep.  N.  Y.  State  Cab. 

Nat.  Hist.,1868,  p.  294;  rev.  ed.,  1868=1870,  p.  337. 

Original  description. — "Body  small,  with  five  radiating  arms, 
arms  elongated  (length  twice  and  a  half  the  width  of  the  body), 
terete,  acute,  composed  of  three  rows  of  plates  [abactinally],  which 
join  above  by  their  lateral  margins.  Beneath  each  upper  lateral 
row  of  plates  there  is  an  inferior  lateral  range  [inframarginal]  vis- 
ible, leaving  the  sulcus  beneath  the  middle  row,  which  is  often 
depressed.  The  dorsal  places  are  somewhat  hexagonal;  those  of  the 
arms  quadrangular;  surface  punctate  or  granulate,  perhaps  from  the 
removal  of  the  spines  covering  the  surface. 

"The  specimen  is  considerably  crushed,  and  two  of  the  arms 
broken  off  at  the  base;  the  madreporiform  tubercle  upon  the  back 
is  not  visible  in  our  specimen.  From  its  condition,  the  structure 
can  not  be  entirely  made  out,  but  it  is  sufficiently  clear  to  enable 
any  one  to  recognize  the  species." 

Emended  description. — Specimen  of  the  usual  size  (No.  3,  Mus. 
Comp.  Zool.)  measures:  R,  =  14  mm.,  r  =  3.5  mm.,  R  =  4r.  The  larg- 
est specimen  (Ottawa,  Billings  collection):  11  =  16  mm.,  r  =  5  mm., 
R  =  3.1r.  The  smallest  New  York  specimen  (No.  26,  Mus.  Comp. 
Zool.):  R  =  7  mm.,  r  =  2.5  mm.,  R  =  2.8r.  Width  of  rays  at  base 
from  2.5  mm.  to  5.5  mm. 

Rays  short,  tapering  rapidly,  convex  abactinally  and  flat  actinally. 
Disk  comparatively  large,  probably  convex  abactinally  during  life. 

Abactinal  area  of  rays  consisting  of  5  ranges  of  large,  thick, 
and  tumid  granular  plates.  The  3  medial  ranges,  when  not 
distorted  by  pressure,  conspicuous,  with  the  11  to  12  plates  of 
each  column  closely  adjoining  and  considerably  elevated  above 
the  inframarginal  ranges.  The  proximal  plates  of  each  supra- 
marginal  range  lie  against  the  large  interradial  plates  and  are 
more  or  less  superposed  on  the  large  axillary  marginals.  In  the 
center  of  the  disk  there  is  a  distinct  highly  convex  plate,  around 
which  is  arranged  a  nearly  complete  ring  of  seven  smaller  pieces 


58  BULLETIN   88,   UNITED  STATES   NATIONAL   MUSEUM. 

and  a  vacant  space  which  may  be  an  anal  opening.  Five  other 
small  quadrangular  plates  are  intercalated,  one  proximally  to  each 
of  the  large  radial  basal  plates.  Outside  of  these  12  intercalary 
plates  there  is  a  ring  of  10  quite  large  and  conspicuous  plates,  5  of 
which  are  radial  and  5  interradial  in  position.  The  radial  plates  are 
largest  and  are  the  basal  pieces  of  5  medial  or  radial  columns,  while 
against  the  5  interradial  plates  rest  the  10  inframarginal  columns. 

Madreporite  abactinal,  quite  small,  situated  immediately  above  a 
large  interradial  plate  and  between  two  basal  supramarginal  plates. 
Its  position  in  relation  to  the  anal  opening  is  apparently  as  in  P. 
incomptus. 

Inframarginal  plates  in  mature  examples  about  14  to  a  col- 
umn, and  when  not  displaced  completely,  inclosing  the  adarnbu- 
lacral  plates  and  margining  the  rays.  The  axils  are  occupied  by  a 
very  large,  oval,  axillary  marginal  plate.  Each  inframarginal  bears 
upon  its  outer  surface  one  to  three  short,  slender,  pointed  spines, 
which  are  finely  striated  longitudinally. 

Adambulacral  plates  small,  subquadangular  in  outline  and  about 
19  in  a  column  in  specimens  having  13  inframarginals.  Each  plate 
bears  on  both  the  outer  and  inner  edges  a  single  spine  and  is  like 
those  of  the  inframarginal  ranges. 

The  oral  armature  consists  of  5  pairs  of  elongate  adambulacrals, 
each  pair  being  situated  directly  orad  of  the  large  axillary  marginal. 

Ambulacral  plates  I— -shaped,  practically  opposite  or  but  very 
slightly  alternating,  one  to  each  adambulacral  plate.  In  the  ex- 
panded medial  portion  the  ambulacralia  are  slightly  superposed  one 
above  the  other  proximally,  while  the  lateral  portion  of  each  plate 
is  very  slender,  leaving  between  adjoining  pieces  comparatively  large 
podial  openings. 

Locality  and  formation. — From  the  Trenton  limestone,  as  follows: 
The  type-specimen  was  found  in  the  " shelly  layers"  at  Trenton 
Falls,  New  York  (Amer.  Mus.  Nat.  Hist.,  No.  199),  and  another 
specimen  was  secured  there  by  Mr.  Rust  (New  York  State  collection). 
Dr.  Walcott  collected  a  slab  with  three  individuals  in  the  Lower 
Trenton  at  Rathbone  Brook,  near  Newport,  Herkimer  County,  New 
York;  and  Mr.  Taylor  got  two  specimens  at  Deerfield,  Oneida  County, 
in  the  same  State  (Mus.  Comp.  Zool.,  Nos.  26  and  3).  Mr.  W.  R. 
Billings  found  a  specimen  in  the  Trenton  at  Lachine,  Quebec,  and 
another  from  Government  House  Bay,  Ottawa. 

Remarks. — H.  matutinus  is  intermediate  in  structure  between  the 
older  E.  narrawayi  and  the  younger  H.  incomptus.  It  is  larger  than 
the  former,  has  more  plates  in  each  of  the  columns,  while  the  ambu- 
lacrals  are  deeply  cut  out  for  the  podia,  which  is  not  the  case  in  H. 
narrawayi.  As  H.  matutinus  is  most  closely  related  to  H.  incomptus 
more  detailed  comparisons  must  be  made  between  them.  Actinally 


KEVISIOISr   OF  PALEOZOIC   STELLEEOIDEA.  59 

the  former  differs  in  the  wider  ambulacral  grooves.  The  difference 
of  greatest  value,  however,  is  found  on  the  abactinal  area  of  the 
disk.  In  both  species  there  is  a  central  disk  plate  surrounded  by  a 
ring  of  accessory  plates.  In  H.  matutinus  there  are  eight  plates  in 
this  ring  and  in  H.  incomptus  there  are  seven.  Between  all  the  basal 
radials  in  the  latter  species  there  is  an  accessory  plate,  or  these  are 
five  in  number,  while  in  the  former  there  are  only  two  such  plates. 
Again,  the  proximal  plates  of  the  supramarginal  columns  in  H. 
incomptus  are  larger  than  any  others  of  the  abactinal  area,  while  in 
H.  matutinus  they  are  smaller  than  the  basal  radials  and  their  form 
and  ornamentation  are  quite  different.  The  madreporites  are  also 
quite  different.  In  general,  H.  incomptus  is  larger,  stouter,  the  rays 
broader  and  the  disk  has  a  greater  number  of  accessory  pieces.  These 
features  are  still  more  pronounced  in  H.  rugosus  (Billings).  Viewing 
these  differences  developmentally,  the  distinctions  are  slight,  which 
proves  the  three  forms  to  be  genetically  related,  but  specifically  the 
differences  are  sufficiently  marked  to  be  regarded  both  morpholog- 
ically and  geologically  as  of  specific  value. 
Apotype.—Csii.  No.  60603,  U.S.JST.M. 

HUDSONASTER  NARRAWAYI  (Hudson). 

Plate  1,  fig.  1;  plate  2,  fig.  1;  plate  4,  fig.  1. 

Protopalseaster  narrawayi  HUDSON,  Ottawa  Naturalist,  vol.  26,  1912,  p.  25,  pis. 
1-3;  vol.  27,  1913,  pp.  77-84,  pis.  8,  9.— RAYMOND,  Ottawa  Naturalist,  vol.  26, 
1912,  pp.  105-107.— HUDSON,  Bull.  N.  Y.  State  Mus.,  No.  164,  1913,  pi.  5  — 
SPENCER,  Mon.  Brit.  Pal.  Asterozoa,  pt.  1  (Palseontogr.  Soc.  for  1913),  1914, 
p.  21,  fig.  19. 

Description. — Specimens  small,  an  average  individual  from  St. 
Paul,  Minnesota;  measuring:  R  =  5  mm.,  r  =  3  mm.,  R  =  1.6r.  Width 
of  ray  at  base  2.7  mm.  The  three  good  specimens  show  only  the 
actinal  side  while  the  fourth  free  siliceous  one  is  too  poorly  preserved 
to  make  out  more  than  the  form. 

Inframarginal  columns  have  from  6  to  9  plates,  while  the  adambu- 
lacrals  and  ambulacrals  each  have  from  11  to  12.  Ambulacral  plates 
large  and  solid,  rectangular,  with  slightly  rounded  ends.  As  these 
plates  are  not  t-  -shaped  as  in  other  species  of  this  genus  it  may  be 
shown  that  this  character  is  of  generic  value,  in  which  case  Proto- 
pal&aster  will  have  to  be  revived. 

Inside  of  each  of  the  large  axillary  plates  lies  a  pair  of  oral  armature 
pieces  that  are  in  form  very  much  like  the  adjoining  adambulacrals. 
From  beneath  these  ossicles  projects  a  stout  and  long,  rounded,  arma- 
ture rod,  the  torus  (a  tooth  or  chisel),  the  5  teeth  meeting  together 
in  the  center  of  the  mouth.  These  armature  rods  and  more  especially 
the  10  pairs  of  ambulacral  armature  pieces  are  seldom  seen  in  fossil 
starfishes,  and  none  shows  it  more  clearly  than  the  Yale  specimen 


60  BULLETIN   88,  UNITED  STATES   NATIONAL  MUSEUM. 

of  H.  narrawayi.  In  the  holotype  of  this  species,  here  illustrated, 
are  seen  additional  pairs  of  oral  armature  ossicles.  These  are  situated 
directly  above  or  dorsal  to  the  pairs  of  large  armature  plates,  and  are 
probably  overlapping  ambulacralia  modified  into  the  actinostomial 
ring. 

Locality  and  formation. — In  the  Black  Kiver  formation,  as  follows: 
The  holotype  was  found  by  Mr.  J.  E.  Narraway  at  City  View,  near 
the  Central  Experimental  Farm  at  Ottawa,  Canada;  it  is  now  in  his 
private  collection.  An  excellent  specimen  was  found  by  Mr. 
Townshend  near  Kirkfield,  Ontario,  and  is  now  in  the  Peabody 
Museum  of  Yale  University.  Many  years  ago  Dr.  Ulrich  found  a 
fine  specimen  at  St.  Paul,  Minnesota,  and  another  good  one  in  the 
Lower  (Glade)  Lebanon  limestone  of  the  Stones  River  series  at 
Shelbyville,  Tennessee.  These  two  specimens  are  in  the  United 
States  National  Museum  (Nos.  60602,  60619).  Mr.  Moritz  Fischer 
secured  a  coarsely  silicified  individual  of  this  genus  at  Curdsville, 
Kentucky,  and  this  is  now  in  the  Beecher  collection  in  the  Yale 
Museum;  it  may,  however,  prove  to  be  of  another  species,  distin- 
guished by  its  stouter  appearance,  wider  disk,  and  smaller  axillary 
plates. 

Remarks. — Originally  the  writer  included  specimens  of  this  form 
under  P.  matutinus,  regarding  them  as  but  young  individuals  of 
Hall's  species.  However,  as  the  specimens  are  all  geologically  older, 
are  always  smaller  and  stouter,  and  with  fewer  plates  in  all  of  the 
columns,  Hudson's  species  is  retained  as  valid.  It  is  the  ancestral 
form  and  the  most  primitive  species  of  Hudsonaster  and  hence  the 
most  primitive  Paleozoic  starfish.  It  is  primitive  because  of  its 
extreme  simplicity  of  structure,  in  that  the  columns  and  plates  are 
reduced  to  the  smallest  number  and  all  of  them  are  closely  adjoining 
and  without  intercalary  plates  of  any  kind.  Then  the  spines  are 
developed  only  on  the  actinal  side  and  as  protection  for  the  podia. 
For  further  information  see  generic  remarks  under  Hudsonaster. 

Cat.  Nos.  60602,  60619,  U.  S.  N.  M. 

HUDSONASTER  MELLERI,  new  species. 

Plate  4,  fig.  2. 

Description. — Of  this  form  there  is  at  hand  but  a  single  poorly 
preserved  individual  showing  the  actinal  side.  It  is  a  more  slender 
species  than  H.  matutinus,  has  a  larger  and  more  rectangular  axillary 
plate,  and  the  proximal  inframarginals  have  each  about  13  to  15 
plates  and  the  adambulacrals  from  18  to  20.  No  ambulacrals  are 
preserved.  The  specimen  measures:  R  =  about  12  mm.,  r  =  3  mm. 
Width  of  ray  at  base  4  mm.,  at  mid-length  3  mm. 

Locality  and  formation. — Found  by  Prof.  Arthur  M.  Miller,  after 
whom  the  species  is  named,  in  the  Lower  Lexington  (Wilmore) 


REVISION   OF  PALEOZOIC   STELLEKOIDEA.  61 

limestone  of  the  Trenton,  in  Fayette  County,  Kentucky.  The 
holotype  is  in  the  collection  of  the  State  University  of  Kentucky  at 
Lexington. 

HUDSONASTER  INCOMPTUS  (Meek). 

Plate  6,  figs.  1,  2. 

"Goniaster"  of  AGASSIZ,  GRAHAM,  ANTHONY,  and  JAMES,  Amer.  Journ.  Sci., 

ser.  2,  vol.  1,  1846,  p.  441  (nomen  nudum). 
Palseaster  incomptus  MEEK,  Amer.  Journ.  Sci.,  ser.  3,  vol.  4,  1872,  p.  275;  Geol. 

Surv.  Ohio,  Pal.,  vol.  1,  1873,  p.  64,  pi.  4,  figs.  5a,  5&. 
Palseaster  simplex  MILLER  and  DYER,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  1, 

1878,  p.  29,  pi.  1,  fig.  6.— MILLER,  N.  Amer.  Geol.  Pal.,  1889,  p.  266,  fig.  380. 
Palseaster  darlcei  MILLER,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  1,  1878,  p.  102, 

pi.  3,  fig.  5. 
Palseaster  clarkana  MILLER,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  3, 1880,  p.  236. 

Original  description  (P.  incomptus). — " Small;  rays  rather  short,  or 
only  about  once  and  a  half  as  long  as  their  breadth  at  their  inner  ends, 
and  rapidly  tapering  to  their  outer  extremities,  which  are  somewhat 
obtusely  angular.  Disk  equaling  in  breadth  the  length  of  the  rays. 
Dorsal  side  of  the  rays  composed  each  of  three  rows  of  pieces  that  are 
wider  than  long,  about  nine  in  each  row,  and  increase  rather  rapidly  in 
size  inward  to  the  margin  of  the  disk,  which  is  composed  of  smaller 
pieces;  a  few  very  minute  pieces  apparently  some  times  occur  between  the 
rows  on  the  dorsal  side  of  the  rays  [none  are  apparent  in  our  material]. 
Surface  of  the  dorsal  pieces  a  little  granular,  but  apparently  without 
spines.  Madreporiform  piece  rather  small,  a  little  oval,  or  almost 
circular  [or  trapezoidal],  nearly  flat,  and  marked  by  fine,  irregularly 
interrupted,  radiating  striae.  Ventral  side  unknown." 

Emended  description. — B,  =  11  mm.,  r  =  6  mm.,  R  =  1 .8r.  Width  of 
ray  at  base  6  mm.  Another  larger  specimen  measures:  R  =  16  mm., 
r  =  7  mm.,  R  =  2.3r.  Width  of  ray  at  base  8  mm.  Smallest  speci- 
men: 11  =  4.5  mm.,  r  =  2  mm. 

Rays  short,  stout,  tapering  rapidly,  convex  abactinally  and  longi- 
tudinally ridged,  flat  actinally.  Disk  large,  probably  very  convex 
abactinally  during  life. 

Abactinal  area  of  rays  consisting  of  five  columns  of  large,  thick, 
tumid,  alternating,  granulose  plates.  In  the  center  of  the  disk  there 
is  a  distinct,  highly  convex  plate  around  which  is  arranged  a  nearly 
complete  ring  of  seven  smaller  pieces  and  a  comparatively  large  open 
space  which  possibly  represents  an  anal  opening.  This  ring  is  fol- 
lowed by  another  composed  of  five  large  interradial  plates  between 
each  of  which  laterally  and  somewhat  centrally  is  intercalated  a 
smaller  plate  radial  in  position.  Laterally  and  distally  to  each  of 
the  five  large  interradial  plates  are  five  large  radial  plates  which  are 
the  basal  pieces  of  the  five  radial  columns.  Against  the  basal  plates 
of  the  medial  ranges  there  adjoin  laterally  two  large  stellate  ossicles, 


62  BULLETIN   88,  UNITED  STATES   NATIONAL  MUSEUM. 

each  of  which  is  the  proximal  plate  of  a  supramarginal  column. 
The  rays  are  margined  by  the  inframarginal  plates.  There  are  10 
plates  in  each  radial  and  9  in  each  supramarginal  column. 

Madreporite  abactinal,  situated  interradially  and  dis tally  against 
the  large  interradial  plate  of  the  second  ring,  which  is  in  front  of  the 
anal  opening,  and  between  two  of  the  proximal  supramarginal  plates. 
It  is  trapezoidal  in  form,  flat,  and  marked  by  very  fine,  dichotomous, 
radial  striae. 

Inframarginal  plates  completely  inclosing  all  other  plates  and  com- 
mon to  both  the  abactinal  and  actinal  surfaces.  Usually  there  are 
9  or  10  in  a  column,  not  counting  the  axillary  plates.  Spines  are 
present  at  least  along  the  inner  edges  of  the  inframarginals. 

Abactinally  the  axillary  marginals  are  not  prominent  but  actinally 
they  are  very  conspicuous.  No  spines  appear  to  be  connected  with 
these  ossicles. 

Adambulacral  plates  small,  subquadrate,  usually  2  to  each 
inframarginal  or  from  18  to  22  plates  in  each  column.  From  4  to 
6  are  situated  around  the  inner  edge  of  each  axillary,  of  which  the 
2  central  ones  are  largest,  being  one  of  the  5  pairs  of  plates 
making  the  oral  armature.  The  adambulacral  plates  originally  bore 
on  their  lateral  and  inner  edges  numerous,  very  short,  thick  spines. 

Ambulacral  plates  nearly  entirely  concealed  by  the  adambulacral 
plates,  apparently  as  numerous  as  the  latter,  and,  so  far  as  can  be 
determined,  like  those  in  P.  matutinus  Hall. 

Locality  and  formation. — In  the  lower,  middle,  and  upper  beds  of 
the  Cincinnatic  (Ordovicic).  Ten  specimens  have  been  studied: 
Four  in  the  Harris  collection  in  the  United  States  National  Museum 
(No.  40882)  from  the  Richmond  formation  (Waynesville  division) 
about  Waynesville,  Ohio;  another  from  the  same  place  and  formation 
in  the  University  of  Chicago  Museum  (Gurley  collection,  No.  10977); 
one  from  the  hill  quarries  in  the  Maysvillian  series  (Vaupel  collection, 
U.  S.  Nat.  Mus.,  No.  60616)  back  of  Cincinnati;  another,  said  to  be 
from  Cincinnati,  in  the  University  of  Toronto  (Walker  collection, 
No.  691  H.  R.);  the  type-specimen,  now  in  the  Museum  of  Com- 
parative Zoology,  also  from  Cincinnati;  one  in  the  Ulrich  collection 
of  the  United  States  National  Museum  (No.  60617),  found  back  of 
Covington,  Kentucky,  in  the  Maysville  formation,  about  315  feet 
above  low-water  mark  in  the  Ohio  River;  and  the  type  of  Palxaster 
simplex  Miller,  found  near  Raysville,  Ohio  (Faber  collection,  Uni- 
versity of  Chicago  Museum,  No.  8830).  The  holotype  of  P.  darkana 
Miller  is  in  Professor  Harper's  collection  at  Cincinnati,  while  another 
specimen  is  in  the  Ulrich  collection  of  the  National  Museum  (No. 
60618). 

Remarks. — The  writer  has  seen  the  type-specimen  of  Palseaster 
simplex  Miller,  which  agrees  with  the  description  and  figure  given 


KEVISION   OF   PALEOZOIC    STELLEEOIDEA.  63 

by  its  author,  and  it  is  like  other  specimens  in  the  Harris  collection 
known  to  be  H.  incomptus  (Meek) .  Of  the  latter,  Meek  only  described 
the  abactinal  area,  while  Miller's  specimen  shows  the  actinal  side. 
The  four  specimens  in  the  Harris  collection  unmistakably  affirm 
that  both  forms  are  identical,  and  since  Meek's  name  has  priority 
it  is  here  accepted.  •* 

For  remarks  as  to  the  relationship  of  this  species  see  H.  matutinus. 

Through  the  kindness  of  Prof.  George  W.  Harper,  principal  of  the 
"Woodward  High  School,  Cincinnati,  Ohio,  the  writer  was  enabled  to 
study  the  type  of  Palseaster  darkana  Miller."  The  specimen  is  a 
little  abraded,  but  shows  all  the  characters  of  H.  incomptus  except  that 
it  is  much  smaller  in  size.  The  abactinal  area  on  a  cursory  examina- 
tion shows  but  three  columns,  but  in  several  places  can  be  seen  pro- 
jecting small  parts  of  the  inframarginal  columns.  The  disk  also  shows 
the  same  general  arrangement  and  number  of  plates  as  in  H.  incomptus. 
There  is  therefore  nothing  except  the  smaller  number  of  plates  in  the 
columns  to  distinguish  P.  darkana  from  H.  incomptus.  Bearing 
in  mind  that  the  former  is  but  one-third  the  size  of  the  latter,  it  is 
not  remarkable  that  P.  darkana  should  have  but  6  or  7  plates 
while  H.  incomptus  has  9  to  10  plates  in  the  same  columns.  The 
entire  difference  is  accounted  for  when  one  regards  P.  darkana  as 
the  young  of  H.  incomptus. 

Another  small  but  very  poorly  preserved  specimen  showing  the 
actinal  area  is  in  the  Ulrich  collection  of  the  National  Museum  and 
agrees  with  the  type  of  P.  darkana.  Its  measurements  are: 
11  =  4.5  mm.,  r  =  2  mm.,  K  =  2.2r. 

The  only  ontogenetic  character  observable  in  these  small  speci- 
mens of  H.  incomptus  is  that  the  columns  have  fewer  ossicles,  and  the 
same  is  true  of  the  abactinal  area  of  the  disk.  It  has  a  central  disk 
plate,  the  first  ring  of  small  plates  and  the  second  ring  of  basal  radial 
and  interradial  plates.  But  no  intercalated  small  plates  radial  in 
position  are  present.  The  second  ring  of  10  plates  and  the  central 
plate  are  the  most  prominent.  If  one  were  theoretically  to  reduce 
the  size  of  the  animal  still  more,  the  plates  of  the  first  ring  would  be 
the  first  to  go  and  the  rays  would  be  simultaneously  very  much 
shortened,  probably  obsolete,  resulting  in  a  hemispheric  nonstellate 
starfish.  The  abactinal  area  seemingly  will  then  have  but  a  central 
disk  plate  and  10  others,  5  radial  and  5  interradial  in  position.  On 
the  actinal  side  there  will  be  but  the  5  axillary  marginal  plates 
separated  from  one  another  by  the  ambulacra!  furrow  and  the 
ambulacralia.  This  hypothetic  animal  therefore  closely  resembles 
a  very  young  Comatula  without  the  stalk  or  column,  and  also  the  stage 
of  living  asterids  following  the  brachiolarial. 

Cat.  Nos.  40882,  60616,  60617,  60618  U.S.N.M. 

50601°— Bull.  88—15 5 


64  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

HUDSONASTER  RUGOSUS  (Billings). 

Plate  3,  fig.  1. 

Palasterina  rugosa  BILLINGS,  Geol.  Surv.  Canada,  Rep.  of  Progress  for  1853-1856, 

1857,  p.  291;  Geol.  Surv.  Canada,  Can.  Org.  Remains,  dec.  3,  1858,  p.  77,  pi. 

9,  figs.  2a-c. 
Palasterina  rugosa  WRIGHT,  Mon.  British  Foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1 

(Paleeontogr.  Soc.  for  1861),  1862,  p.  27. 
Hudsonaster  rugosa  STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56, 1900, 

pp.  218,  224,  225. 

Original  description. — "Two  inches  [not  over  47  mm.]  in  diameter, 
rays  five,  acute  at  their  apices  and  rapidly  enlarging  to  a  breadth 
of  four  lines  [about  11  mm.]  at  the  disk,  which  is  eight  lines  [about 
17  mm.]  in  width.  The  specimen  shows  the  upper  [or  abactinal] 
side  of  the  fossil  only;  some  of  the  plates  are  absent  from  the  center 
of  the  disk,  but  those  which  remain  are  very  prominent  in  their 
centers,  and  roughly  ornamented  by  four  or  five  deep  crenulations 
or  furrows  from  near  the  center  to  the  edges,  producing  a  star-like 
appearance  resembling  a  half-worn  plate  of  Glyptocrinus  decadac- 
tylus;  their  diameter  is  from  one  to  two  lines  [largest  diameter  4  mm.]. 

"The  rays  are  composed  (at  least  the  backs  and  sides  of  them) 
of  four  rows  of  plates  [due  to  distortion,  a  careful  analysis  shows 
five  columns]  which  are  so  very,  prominent  that  they  appear  to  be 
almost  globular,  and  even  pointed  in  their  centers,  the  central 
[radial]  rows  are  the  smallest  [as  in  H.  incomptus]',  the  first  four 
plates  of  the  outer  [supramarginal]  row  occupy  three  lines  in  length, 
and  of  the  inner  [radial]  rows  nearly  as  many.  Toward  the  point 
of  the  arm  all  diminish  rapidly  in  size. 

"Beneath  the  outer  [or  supramarginal]  rows  two  others  can  be 
seen  [the  inframarginal],  which  are  probably  the  outer  marginal  plates 
of  the  under  [or  actinal  side],  corresponding  to  those  of  Petrasier 
rigidus." 

Locality  and  formation. — Richmondian  series,  Charleton  formation, 
at  Charleton  Point,  Anticosti  Island.  Two  specimens  collected  by 
J.  Richardson  are  now  in  the  Victoria  Memorial  Museum  at  Ottawa, 
Canada  (No.  1999). 

Remarks. — The  same  description  was  republished  in  1858  with 
the  addition  of  three  figures.  These,  and  a  direct  examination  of 
the  two  type-specimens,  show  that  this  species  clearly  belongs  to 
Hudsonaster  and  that  it  is  closely  related  to  H.  incomptus.  The 
smaller  free  specimen  preserves  a  portion  of  the  disk  and  parts  of 
two  rays  and  shows  clearly  the  presence  of  a  single  large  axillary 
plate.  H.  rugosus,  however,  attained  a  considerably  larger  growth, 
has  a  greater  number  of  plates  in  each  column  and  these  are  described 
as  "almost  globular,"  while  in  H.  incomptus  the  abactinal  plates  are 
very  convex  but  not  globular.  Then  the  basal  supramarginal  and 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  65 

radial  plates  are  much  more  decidedly  ornate.  Each  of  the  supra- 
and  inframarginal  columns  has  14  plates  against  9  in  H.  incomptus, 
and  of  adambulacrals  there  are  not  less  than  24  in  a  column  against 
18  to  22  in  the  same  form.  All  of  the  ossicles  are  as  strongly  papillose 
but  not  more  so  than  in  H.  incomptus.  The  detail  of  the  disk  is  not 
determinable. 

HUDSONASTER  BATHERI,  new  species. 
Plate  3,  fig.  3. 

Tetraster  wyville-thomsoni  NICHOLSON  and  ETHERIDGE  (part),  Mon.  Silurian 
Foss.  Girvan  Dist.,  Ayrshire,  fasc.  3,  1880,  p.  324,  pi.  21,  figs.  1,  2  (not  the 
other  figs.). 

A  small  Hudsonaster.  R  =  6  mm.,  r  =  2.7  mm.  The  largest 
specimen:  R  =  8  mm. 

Actinal  side  only  known.  Inframarginal  columns  the  largest, 
with  8  or  9  distinctly  tuberculate  plates.  Inside  of  these  are 
the  columns  of  narrower  and  slightly  shorter  adambulacrals  that 
lie  somewhat  below  the  level  of  the  inframarginals ;  there  are 
10  or  11  of  these  plates  bounding  the  ambulacral  grooves,  and  the 
pieces  of  adjacent  columns  are  opposite  or  nearly  opposite  one 
another.  The  ambulacral  grooves  are  very  narrow  and  deep  and 
no  ambulacralia  are  discernible. 

Formation  and  locality. — Dr.  F.  A.  Bather  made  wax  squeezes 
for  the  writer  from  three  natural  molds  in  the  collection  of  Mrs. 
Robert  Gray,  Edinburgh;  the  originals  are  from  the  Upper  Ordovicic 
of  Thraive,  Girvan  District,  Scotland.  The  holotype  is  the  specimen 
illustrated  as  above  cited. 

Remarks. — Nicholson  and  Etheridge  confused  at  least  one  of  these 
specimens  with  their  Tetraster  wyville-thomsoni ,  a  species  of  totally 
different  construction,  a  cryptozonian,  described  elsewhere  in  this 
work.  Actinally  the  new  species  is  in  harmony  with  Hudsonaster 
and  although  the  abactinal  side  is  unknown,  it  is  thought  that  it 
will  be  found  to  be  like  that  in  H.  matutinus. 

Cat.  No.  60601,  U.S.N.M. 

Genus  SILURASTER  Jaekel. 
Text  fig.  6. 

Siluraster  JAEKEL,  Zeits.  geol.  Ges.,  vol.  55,  1903,  Protokol,  p.  13  (106),  figs.  2, 
3,  on  p.  108. — SPENCER,  Mon.  Brit.  Pal.  Asterozoa,  pt.  1  (Palaeontgr.  Soc.  for 
1913),  1914,  p.  18. 

Description. — "A  typical  asterid  with  opposite  ambulacralia  and 
with  well-developed  marginalia,  therefore  a  true  form  of  Phanero- 
zonia.  The  strongly  folded  madreporite  lies  dorsally  in  an  inter- 
radius." 


66 


BULLETIN 


UNITED   STATES    NATIONAL   MUSEUM. 


£l2 


From  the  two  excellent  illustrations  the  following  is  made  out: 
Inframarginals  conspicuous  and  as  large  as  the  adambulacrals. 
Both  columns  finely  tuberculate,  with  the  ossicles  of  each  alternating 
with  one  another.  Proximally  the  inframarginals  of  adjacent  rays 
rest  on  a  somewhat  larger  axillary  plate.  The  interbrachial  areas 
are  therefore  made  up  of  single  axillary  ossicles  (Jaekel's  marginal 
oral)  and  in  front  of  these  lies  a  pair  of  pointed  adambulacrals,  the 
conspicuous  pieces  of  the  oral  armature.  These  are  perforated  for 
the  continuation  of  the  ring  canal.  The  podial  openings  as  usual 
lie  in  the  corners  of  four  adjacent  adambulacrals  and  ambulacrals, 

but  there  is  a  de- 
cided tendency  to 
restrict  them  to 
only  one  of  the  am- 
bulacral  corners. 

Abactinal  area 
unknown. 

Remarks.  —  This 
genus  appears  to  be 
closely  related  to 
Hudsonaster,  but 

FIG.  6.-SILT7RASTER  PERFECTUS  (JAEKEL'S  FIGURE  3).     Oj  TO  Og,  AMBU-  ,  -1    o,  -7  ,  • 

LACRALIA  OF  ONE  SIDE;  ABOVE  THESE  ddi  TO  ddg,  THE  ADAMBULACRALIA,     l  l6'    1 

adi  AS  MOUTH  CORNER  PIECE;  dfg,  PODIAL  GROOVES;  dpff,  PODIAL  OPEN-     DlOrC      fully      WOrked 

INGS;  m,  INFRAMARGINALIA;  mo,  THE  SINGLE  AXILLARY  INFRAMARGINAL;          ,  • ,       «n 

RC,  RING-CANAL  IN  MOUTH  CORNER  PLATES.  °Ut  lt}  ^  ^maUl  aS 

an  obscure  genus. 

Genoholotype  and  only  species. — S.  perfectus  Jaekel.  Ordovicic 
(D4),  Zahorzan,  Bohemia. 

Family  PAL^ASTERID^E  Gregory  (emend.). 

Palaeasteridae  (part)  MILLER,  N.  Amer.  Geol.  Pal.,  1889,  p.  216. — GREGORY,  Geol 
Mag.,  dec.  4,  vol.  6,  1899,  p.  344  (contains  Palseasterinae,  Xenasterinse,  and 
Lindstromasterinse);  Treat.  Zool.,  vol.  3,  Echinoderma,  1900,  p.  250. 

Palsecisterinas  SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63, 
1910,  p.  244. 

Palxgoniasteridx  (part)  STURTZ,  Palaeontographica,  vol.  36,  1890,  p.  246  (contains 
Aspidosomella  and  Pal&aster). 

Primitive,  derived,  five-rayed  Phanerozonia  with  the  ambulacrals 
slightly  alternate  or  opposite.  Interbrachial  arcs  incipient  or  some- 
what enlarged,  and  occupied  by  single  axillary  marginal  plates.  No 
accessory  interbrachial  or  axillary  interbrachial  plates  present,  but 
there  are  developed  accessory  abactinal  ray  ossicles.  Actinal  plates 
consisting  of  ambulacrals,  adambulacrals,  and  inframarginals.  Mad- 
reporite  abactinal. 

Contains : 

Palseaster  Hall. 
Australaster,  new  genus. 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  67 

Genus  PALSEASTER  Hall  (emend.). 
Plate  7,  figs.  1-4. 

Palseaster  HALL,  Nat.  Hist.  N.  Y.,  Pal.,  vol.  2,  1852,  p.  247;  Twentieth  Rep.  N.  Y. 

State  Cab.  Nat.  Hist.,  1868,  p.  282;  rev.  ed.,  1868=1870,  p.  324.— ZITTEL, 

Handb.  Pal.,  vol.  1,  1879,  p.  452. 
Palseaster  NICHOLSON  and  ETHERIDGE  (part),  Mon.  Silurian  Foss.  Girvan  Dist., 

Ayrshire,  fasc.  3,  1880,  p.  319. 
(Not  Palseaster  SALTER,  Ann.  Mag.  Nat.  Hist.,  ser.  2,  vol.  20,  1857,  p.  323=  Uras- 

terella.) 
(Not  Palseaster  of  most  AUTHORS.) 

Generic  characters. — Disk  small  and  without  distinct  interbrachial 
arcs.  Rays  five  and  slender. 

Abactinal  area  of  disk  centrally  occupied  by  a  large  plate,  then  a 
ring  of  5  separated,  somewhat  smaller,  radially  situated  ossicles, 
and  inside  the  axillary  pieces  there  are  5  subtriangular  interradial 
plates,  against  which  lie  10  very  large  and  conspicuous  proximal 
supramarginal  plates.  Between  the  central,  radial,  and  interradial 
plates  are  numerous  small  accessory  pieces  which  separate  the  pri- 
mary ossicles  one  from  another.  These  accessory  plates  also  continue 
to  crowd  from  the  disk  into  the  rays  between  the  supramarginals, 
and  thus  take  the  place  of  the  radial  columns,  but  are  absent  in  the 
distal  third  of  the  rays.  Each  ray  has  therefore  4  conspicuous 
columns  of  plates,  the  2  supramarginals  situated  inwardly  of  the 
2  marginal  inframarginals.  The  former  columns  terminate  in  10 
very  large  proximal  plates  situated  in  the  axils  of  the  disk,  while  the 
inframarginals  rest  against  the  5  very  large  actinal  axillary  margi- 
nal pieces.  All  of  the  large  plates  are  centrally  smooth,  bordered  by  a 
pustulose  area. 

Madreporite  abactinal,  of  medium  size,  circular  in  outline,  and 
radially  striate.  It  lies  on  top  of  two  proximal  supramarginal  plates 
and  the  adjoining  interradial  plate. 

Inframarginal  plates  thick  and  large,  about  as  many  in  a  column 
(13)  as  in  those  of  the  supramarginals  (13  or  14).  The  latter  do 
not  completely  overlie  the  inframarginals,  since  these  bound  the 
rays  both  actinally  and  abactinally.  The  inframarginal  plates,  like 
the  plates  of  the  abactinal  area,  have  each  a  large,  smooth,  central 
space  encircled  by  a  pustulose  area.  From  their  inner  sides  articu- 
late short,  thick,  blunt  spines,  of  which  there  are  apparently  not 
more  than  2  to  each  inframarginal  plate. 

Axillary  marginal  plates  large,  hexagonal,  one  in  each  axil  and 
common  to  both  sides  of  the  disk  axils. 

Adambulacral  plates  small,  tumid,  alternating  in  the  main  with 
the  inframarginal  plates  throughout  the  distal  two-thirds  of  the  rays, 
but  toward  the  mouth  there  are  a  few  more  adambulacrals  than  in- 
framarginals. (In  the  type-specimen  there  are  13  of  the  latter  in  a 
column  to  16  of  the  former.)  Oral  armature  consists  of  at  least  5 
pairs  of  drawn  out  and  pointed  basal  adambulacrals.  Along  the  inner 


68  BULLETIN   88,   UNITED  STATES   NATIONAL   MUSEUM. 

side  of  each  adambulacral  plate  there  is  a  linear  brush  of  from  5 
to  7  short,  slender  spines. 

Ambulacral  grooves  very  narrow,  tapering  but  very  slowly.  Am- 
bulacral  plates  obscured  by  the  rock  but  apparently  very  short,  one 
to  each  adambulacral  and  placed  opposite  one  another. 

GenoJiolotype  (type  by  monotypy)  and  only  species. — P.  niagarensis 
Hall.  Siluric  (Rochester  shale). 

Remarks. — To  this  genus  has  been  erroneously  referred  a  multitude 
of  Paleozoic  starfishes.  It  is  to  the  starfishes  what  Terebratula  and 
Rhynchonella  used  to  be  among  the  brachiopods— a  general  dumping 
ground  for  Paleozoic  forms.  This  lack  of  generic  conception  regarding 
Palseaster  lies  somewhat  in  the  fact  that  Hall's  original  diagnosis  is 
very  meagre  and  that  he  did  not  describe  nor  illustrate  the  abactinal 
surface,  probably  the  most  important  area  amongst  Paleozoic  aster- 
ids  for  specific  and  generic  differentiation.  Of  the  twenty-four  Amer- 
ican species  listed  under  Palseaster  by  S.  A.  Miller1  only  one  now 
appears  to  belong  there,  the  genotype.  All  others  are  here  referred 
to  Hudsonaster,  Urasterella,  Mesopalseaster,  Promopalseaster,  Anorth- 
aster,  Devonaster,  and  Neopalseaster. 

No  new  material  of  this  genus  accessible  to  the  writer  appears 
to  have  been  found  since  Colonel  Jewett  discovered  the  original 
two  specimens  of  Palseaster  niagarensis.  The  writer  therefore  had  to 
make  the  most  of  this  material,  and  to  determine  the  structure  of 
the  abactinal  area  he  worked  away  much  of  the  blue  shale  from  the 
back  of  the  one  good  specimen.  The  finer  detailed  structure  was  then 
revealed  by  cleaning  with  caustic  potash. 

In  1858  Billings  proposed  the  genus  Stenaster2  and  writes-  that 
"as  it  has  been  suggested  that  the  two  species  hereinafter  described 
should  be  referred  to  Palseaster,  I  give  the  following  figure  of  the  genus 
in  order  to  show  the  difference."  This  figure  is  a  good  reproduction 
of  Hall's  figure  27.  Billings  then  points  out  that  "if  the  large  plates 
which  border  the  grooves  in  Palseaster  be  adambulacral,  then  there 
are  only  five  oral  plates,  whereas  in  Stenaster  there  are  ten.  But  if 
they  be  not  adambulacral  but  marginal  plates,  then  Palseaster  must 
have  both  marginal  and  adambulacral  [the  correct  view],  while 
Stenaster  has  only  the  latter." 

Hall's  generic  description  is  very  meager  and  his  figures  give 
the  impression  that  the  rays  bear  but  a  single  column  of  marginal 
spiniferous  plates.  With  this  evidence  one  can  understand  why 
Billings  was  in  doubt  as  to  whether  these  plates  are  inframarginals 
or  adambulacrals  and  therefore  the  uncertainty  as  to  the  nature  of 
the  five  large  axillary  marginal  plates.  If,  however,  he  had  read 
Hall's  accurate  specific  description,  Billings  would  have  seen  that  an 
important  discrepancy  -existed  between  the  description  and  figures. 

1  North  American  Geology  and  Palaeontology,  1889,  p.  265. 

2  Geol.  Surv.  Canada,  Canadian  Organic  Remains,  dec.  3, 1858,  pp.  77,  78. 


REVISION   OF   PALEOZOIC    STELLEROIDEA.  69 

Hall  writes:  " Lower  side  of  arms  showing  two  ranges  of  plates  on 
each  side  of  the  avenue,  the  outer  range  composed  of  strong  hex- 
agonal plates,  with  an  inner  range  of  smaller  ones  alternating,  the  latter 
usually  covered  by  tufts  of  spines."  The  type-specimen  clearly 
shows  columns  of  adambulacral  and  inframarginals  bordering  the 
ambulacral  grooves  and  that  in  each  axil  there  is  a  single  large  axillary 
marginal  plate.  This  matter  need  not  here  be  followed  further  than 
to  add  that  Stenaster  originally  included  two  generic  types,  both  of 
which  are  widely  different  from  Palseaster.  On  the  other  hand,  Hall1 
is  in  error  in  regarding  all  of  Stenaster  as  synonymous  with  Uraster- 
ella  McCoy,  a  name  never  properly  defined  and  finally  abandoned  by 
its  author.  Billings  originally  referred  to  Stenaster,  S.  salteri,  and 
S.  pulcTiellus.  The  latter  is  certainly  congeneric  with  the  type  of 
Urasterella  as  illustrated  by  Salter,  but  the  former  is  quite  different, 
as  is  pointed  out  elsewhere  in  the  remarks  on  Stenaster,  which  is  a 
good  genus. 

Palseaster  in  many  respects  reminds  one  of  Hudsonaster,  and  the 
actinal  generic  characters  may  be  regarded  as  alike  in  both.  The 
abactinal  area  is  also  similar,  but  in  Hudsonaster  there  are  five  columns 
with  decidedly  fewer  plates,  while  in  Palseaster  there  are  no  radial 
columns.  The  former  genus  is  the  more  primitive  one  and  the 
progression  in  differentiation  toward  Palseaster  appears  to  be  as  fol- 
lows: In  Hudsonaster,  the  rays  throughout  are  composed  of  five 
columns  of  plates,  two  inframarginals,  two  supramarginals,  and  one 
radial.  In  Palseaster,  there  are  but  four  columns  in  the  outer  third 
of  the  rays,  two  infra-  and  two  supramarginals,  but  in  the  proximal 
two-thirds  where  the  radials  are  also  absent,  their  place  is  occupied 
by  numerous  small,  irregular  accessory  plates.  This  introduction  of 
numerous  supplementary  plates  also  takes  place  to  a  far  greater 
extent  on  the  disk,  where  they  are  crowded  in  between  the  larger 
central  and  the  five  basal  radial  plates. 

The  primitive  disk  structure  of  Palseaster  is  in  large  part  again 
repeated  in  Neopalseaster,  but  otherwise  the  two  genera  are  different. 

PALSEASTER  NIAGARENSIS  Hall. 

Plate  7,  figs.  1^. 

Palseaster  niagarensis  HALL,  Nat.  Hist.  N.  Y.,  Pal.,  vol.  2,  1852,  p.  247,  pi. 
51,  figs.  21-23  (not  p.  352,  pi.  85,  figs.  8-10,  possibly  an  undescribed 
species). — BILLINGS,  Geol.  Surv.  Canada,  Can.  Org.  Rem.,  dec.  3,  1858,  p. 
78,  fig.  1.— HALL,  Twentieth  Hep.  N.  Y.  State  Cab.  Nat.  Hist.,  1868,  p.  282; 
rev.  ed.,  1868=1870,  p.  324.— QUENSTEDT,  Petrefactenkunde  Deutschlands, 
vol.  4,  1876,  p.  73,  pi.  92,  figs.  32,  33.— HUDSON,  Bull.  N.  Y.  State  Mus., 
No.  164,  1913,  pis.  9,  10,  12,  13. 

Original  description. — "Body  stellate;  disk  small;  arms  short,  terete 
with  a  deep  avenue  on  the  lower  side,  which  is  margined  by  strong 
short  spines;  centre  of  plates  (in  the  fossil)  nearly  smooth,  margins 

i  Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  rev.  ed.,  1808=1870,  p.  325. 


70  BULLETIN    88,   UNITED   STATES   NATIONAL   MUSEUM. 

strongly  granulate;  lower  side  of  arms  showing  two  ranges  of  plates 
on  each  side  of  the  avenue,  the  outer  range  composed  of  strong 
hexagonal  plates,  with  an  inner  range  of  smaller  ones  alternating, 
the  latter  usually  covered  by  tufts  of  spines;  a  large  pentagonal  plate 
inserted  at  the  base  of  the  arms,  on  the  lower  side. 

"In  this  species,  the  arms  are  about  twice  as  long  as  the  width  of 
the  disk.  There  are  about  15  or  16  plates  in  each  range  from  the 
base  to  the  apex  of  the  arms.  The  range  of  the  plates  margining 
the  avenue  are  usually  not  visible,  the  whole  being  covered  by  the 
short  spines,  which  also  partially  fill  the  avenue. " 

In  1870  Hall  added  the  following  important  observations: 

"I  have  distinctly  recognized  the  two  ranges,  marginal  and 
adambulacral  plates;  but  the  inner  ones  are  not  shown  in  the  figure 
as  they  should  have  been,  while  the  large  plate  at  the  axil  of  the  ray 
(though  the  adjacent  small  oral  plates  of  the  inner  range  are  not 
seen)  is  evidently  part  of  an  incomplete  series,  and  clearly  belongs 
to  the  marginal  range. 

"The  genus  Palseaster  has  two  ranges  of  plates  on  each  side  of  the 
ambulacral  groove;  marginal  and  adambulacral  plates  on  the  lower 
side,  besides  ambulacral  or  poral  plates.  The  upper  or  dorsal  side 
has  three  or  more  ranges  of  plates." 

Emended  description. — Measurements:  R=1S  mm.,  r=5  mm, 
Width  of  ray  at  base  5  mm. 

Rays  long,  slender,  tapering  slowly;  abactinally  strongly  convex 
and  longitudinally  ridged;  flat  actinally.  Disk  comparatively  large, 
strongly  convex  and  probably  abruptly  elevated  above  the  rays 
abactinally.  There  are  no  interbrachial  arcs,  but  the  five  axillary 
marginal  plates  occupy  the  axils  and  are  also  partially  visible 
abactinally. 

Abactinal  area  of  rays  consisting  of  4  columns  of  large,  thick, 
convex  plates.  These  are  the  supra-  and  inframarginal  columns. 
The  supramarginal  plates  of  each  ray  are  distally  in  contact  with 
one  another  along  the  mid-line,  but  proximally  they  are  forced  more 
and  more  apart  by  a  series  of  small,  irregular,  accessory  plates.  In 
the  center  of  the  disk  there  is  a  small,  convex  disk  plate  around  which 
are  situated  radially  5  other  small  ossicles,  all  of  which  are  sepa- 
rated from  each  other  apparently  by  a  considerable  number  of  minute 
intercalary  pieces.  Just  inside  of  the  axils  are  5  large,  sub  triangular, 
uiterradial  plates  and  adjoining  these  directly  are  10  large  and  con- 
spicuous ones,  the  proximal  plates  of.  the  supramarginal  columns. 
In  each  column  there  are  about  13  plates,  not  counting  the  proximal 
piece.  Between  all  of  the  larger  plates  of  the  disk  and  for  two- 
thirds  the  length  of  the  rays  between  the  supramarginals,  there  are 
numerous  small,  convex,  irregularly  shaped,  accessory  plates.  All 


BEVISIOK   OF   PALEOZOIC   STELLEROIDEA.  71 

the  larger  ossicles  of  both  sides  are  centrally  smooth,  surrounded  by 
a  finely  pustulose  border. 

Madreporite  situated  interradially  and  distally  upon  the  three 
large  plates  just  inside  an  axillary  marginal  plate,  two  of  which  are  the 
proximal  plates  of  supramarginal  columns  of  adjoining  rays.  It  is 
circular  in  outline,  flat,  and  radially  striated. 

Inframarginal  plates  occupying  the  outer  edges  of  both  the  actinal 
and  ab actinal  areas;  from  13  to  15  plates  hi  each  column.  The 
supramarginal  plates  are  situated  above  and  inside  the  inframarginals, 
which  inwardly  bear  short,  thick,  club-shaped  spines.  Otherwise 
they  are  ornamented  like  the  abactinal  plates. 

Adambulacral  ossicles  small,  subquadrate,  each  one  alternating 
distally  with  an  inframarginal  plate,  but  proximally  they  are  some- 
what more  numerous,  there  being  from  17  to  probably  20  in  a  column. 
On  these  plates  lie  two  series  of  spines — the  two  short,  thick,  club- 
shaped  ones  of  each  mframarginal  plate — while  on  the  inner  side  of 
each  adambulacral  there  is  inserted  a  linear  brush  of  from  five  to  seven 
slender,  short  spines  that  are  outwardly  and  laterally  directed. 

Ambulacral  grooves  very  narrow,  deep,  and  gradually  tapering. 
Ambulacral  plates  not  well  seen  but  apparently  very  short,  one  to 
each  adambulacral  and  directly  opposite  one  another. 

Axillary  marginal  plates  five  in  number,  very  large  and  conspicuous 
actmally,  also  showing  slightly  abactinally. 

Locality  and  formation. — The  only  good  specimen  was  found  many 
years  ago  by  Col.  E.  Jewett  in  the  Siluric  (Rochester  shale)  at  Lock- 
port,  New  York.  A  fragment  of  the  ray  of  a  much  larger  individual, 
nearly  twice  the  size  of  this  type,  was  found  by  the  same  gentleman 
at  the  same  place.  These  specimens  are  now  in  the  paleontological 
museum  of  Cornell  University  (No.  7331)  and  were  presented  by 
Hon.  Ezra  Cornell.  Long  after  the  study  of  the  form  was  com- 
pleted another  specimen  preserving  two  rays  and  showing  the  actinal 
side  was  learned  of  in  the  University  of  Toronto  (Walker  collection, 
No.  1008).  It  was  found  at  Grimsby,  Ontario. 

Remarks. — This  species  has  never  been  well  described  nor  figured, 
and  has  accordingly  led  to  endless  generic  confusion.  Almost  any 
Paleozoic  starfish  with  large  marginal  plates  has  been  referred  to 
Pal&aster.  This  lack  of  generic  conception  was  partially  due,  as 
stated  above,  to  the  fact  that  the  abactinal  side  remained  unknown. 
The  specimen  lies  imbedded  in  blue  shale  showing  the  actinal  area, 
and  the  abactinal  side  was  revealed  by  the  writer  by  cutting  away 
the  slab  to  the  starfish  and  then  developing  the  individual  plates 
with  caustic  potash. 

In  a  general  way  Palseaster  niagarensis  resembles  several  species  but 
all  are  distinguished  by  generic  characters.  The  nearest  one  is 
Hudsonaster  incomptus  from  the  Cincinnatic  strata,  but  it  differs  at 


72  BULLETIN   88,  UNITED  STATES   NATIONAL  MUSEUM. 

once  in  having  five  instead  of  four  columns  of  large  abactinal  plates. 
There  are  also  a  far  less  number  of  the  accessory  plates  so  numerous 
on  the  disk  and  the  proximal  medial  areas  of  the  rays  in  Palseaster 
niagarensis. 

Hall1  refers  a  fragment  to  this  species  which  clearly  is  of  quite 
another  species.  It  is  very  far  removed  from  P.  niagarensis  and 
for  the  present  need  not  be  considered.  The  specimen  hus  not  been 
seen  by  the  writer. 

AUSTRALASTER,  new  genus. 
Plate  4,  fig.  4. 

Palseaster  ( Monaster)  ETHERIDGE,  jr.  (part),  Mem.  Geol.  Surv.  New  South  Wales, 

Pal.,  No.  5,  pt.  2,  1892,  p.  74. 

Monaster  GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6,  1899,  p.  345  (not  of  Etheridge,  jr.). 
Australaster  SCHUCHERT,  Fossiliiim  Catalogus,  Animalia,  pt.  3,  April,  1914,  p.  12. 

Austral=sout1n.eTn  and  aster.  A  Paleozoic  starfish  restricted  to 
Australia. 

Generic  diagnosis. — Animal  attaining  a  very  large  size,  with  five 
long;  slender,  almost  straight-sided  rays,  terminating  bluntly. 
Interbrachial  areas  comparatively  small,  widely  concave,  and  occu- 
pied by  ponderous,  single,  axillary  marginals  and  inframarginal 
plates. 

Abactinal  area  unknown  (see  A.  (?)  stutcfiburii) . 

Actinally  the  animal  is  bounded  by  inframarginal  plates  which 
however  do  not  appear  to  be  present  in  the  distal  third  of  the  rays. 
If  such  plates  are  present  in  these  outer  regions,  they  are  either 
very  small  or  gradually  pass  from  the  actinal  to  the  abactinal  area, 
the  latter  condition  occurring  ha  related  genera.  The  inframarginals 
in  the  outer  third  of  the  rays  are  small,  subquadrangular,  and  rounded, 
thence  they  increase  rapidly  in  size  proximally,  become  decidedly 
transverse,  and  in  the  axils  the  columns  abut  against  a  very  large 
axillary  inf  ramarginal.  The  largest  plate  is  the  axillary  marginal,  orad 
to  which  occur  the  pairs  of  enlarged  oral  armature  ossicles.  The 
inframarginals  appear  to  be  nearly  smooth  and  devoid  of  spines. 

The  adambulacrals  in  the  distal  third  of  the  rays  are  numerous, 
very  short,  but  quite  wide — that  is,  are  decidedly  transverse,  and 
decrease  rather  rapidly  hi  breadth  toward  the  tips  of  the  rays. 
Proximally  these  plates  also  decrease  quickly  in  width  and  rapidly 
pass  inside  of  the  inframarginals.  Inside  of  the  axillary  marginals 
the  plates  are  again  prominent  and  especially  the  pairs  of  oral  arma- 
ture pieces.  Each  adambulacral  plate  bears  prominent  tubercles 
for  the  articulation  of  stout  but  short  spines.  The  columns  have 
the  pieces  arranged  with  a  decided  slant  outward  and  distally. 

i  Palaeontology  of  New  York,  vol.  2, 1852,  p.  352  and  pi.  85,  figs.  8-10. 


REVISION   OF   PALEOZOIC   STELLEEOIDEA.  73 

Ambulacral  furrows  deep,  slender  and  tapering  slowly.  Ambu- 
lacra! plates  unknown.  Oculars  not  present. 

Genoholotype.  Palseaster  (Monaster)  giganteus  Etheridge,  jr.  The 
specific  description  and  the  bibliographic  references  are  included  in 
the  generic  diagnosis. 

Kes  trie  ted  to  the  Lower  Marine  series  of  the  "  Permo-Carbon- 
iferous"  of  New  South  Wales. 

AUSTRALASTER(P)  STUTCHBURH  (Etheridge,  jr.). 

Palxaster  (Monaster)  stutchburii  ETHERIDGE,  jr.,  Mem.  Geol.  Surv.  New  South 

Wales,  Pal.,  No.  5,  pt.  2,  1892,  p.  73,  pi.  13,  fig.  1. 
Monaster  stutchburii  GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6,  1899,  p.  346. 

This  species  is  found  associated  with  A.  giganteus  and  its  preserva- 
tion is  such  that  the  form  is  very  imperfectly  known.  In  some 
respects  it  resembles  that  species  and  may  prove  to  be  a  smaller 
specimen  of  it,  but  until  the  disk  marginals  are  known  the  differ- 
ences will  remain  obscure. 

If  A.  (?)  stutchburii  has  the  large  disk  marginals  of  Australaster, 
it  then  seemingly  will  have  the  essential  structure  of  that  genus. 
Regarding  this  the  writer  wrote  Professor  Etheridge  in  1900  and 
he  replied  that  " axillary  plates  are  not  visible  in  the  specimen". 

Since  the  abactinal  area  of  A.  giganteus  is  unknown,  it  is  desirable 
to  give  here  the  abactinal  structure  in  A.  (?)  stutchlmrii,  as  it  may 
prove  to  be  congeneric  with  A.  giganteus. 

"  Abactinal  surface  moderately  convex,  bearing  several  (five  or 
six)  rows  of  small  convex  polygonal  plates,  inclusive  of  the  margi- 
nal pieces,  and  becoming  much  crowded  at  the  apices  of  the  rays, 
where  they  form  oblique  rows."  If  these  plates  throughout  the 
rays  are  as  figured  by  Etheridge  for  the  distal  ends,  the  strongly 
quincuncial  arrangement  of  the  polygonal,  closely  adjoining  plates 
is  another  good  generic  character  for  Australaster. 

PROMOPAL^ASTERID^E,  new  family. 

Progressive  Phanerozonia  with  distinct  columns  of  inframar- 
ginal  plates.  Interbrachial  areas  more  or  less  complex,  composed 
either  of  inframarginals,  axillary  interbrachials  and  ambulacrals, 
or  of  these  with  the  addition  of  interbrachial  marginals  and  acces- 
sory interbrachials,  or  entirely  of  adambulacral  plates.  Ambu- 
lacrals as  a  rule  opposite,  but  they  may  also  be  slightly  alternating. 
Podial  openings  through  the  sutures  in  the  lateral  corners  of  the 
ambulacral  plates,  but  proximally  a  few  alternate  pores  may  grad- 
ually pass  medially,  when  there  are  four  columns  of  podial  openings 
in  each  ambulacral  furrow. 

Madrsporite  abactinal. 

Abactinal  plates  very  numerous,  generally  small,  either  in  dis- 
tinct columns  or  rows  or  without  either  arrangement.  The  radial 


74  BULLETIN    88,   UNITED   STATES   NATIONAL   MUSEUM. 

and  supramarginal  columns  may  be  very  distinct  or  may  be  ob- 
scured as  such.     Accessory  ossicles  always  more  or  less  abundantly 
developed. 
Contains  : 

Mesopalaeasterinae. 

Promopalseas  fcerinse. 

Anorthasterinse. 


new  subfamily. 

Palxocwnidde  GREGORY,  Treat.  Zool.,  vol.  3,  Echinoderma,  1900,  p.  254. 
Primitive  Promopalseasteridse  with  the  interbrachial  areas  small, 
composed  of  one  pair  of   inframarginals,  single  axillary  infcerbra- 
chials,  and  the  adambulacral  plates. 
Contains  : 

Mesopalszaster,  new  genus. 
Spaniaster  Schondorf. 
Miomaster  Schondorf. 
Devonaster,  new  genus. 

MESOPAL^EASTER,  new  genus. 
Plates  7-11. 

Palseaster  (part)  of  AUTHORS. 

fArgaster  HALL,  Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  1868,  p.  287:  rev. 

ed.,  1868=1870,  p.  329. 
Mesopalseaster  SCHUCHERT,  Fossilium  Catalogus,  Animalia,   pt.   3,  April,  1914, 

p.  24. 

Meso  =  middle,  and  Palseaster.  Not  the  largest  of  Palseasters  of 
authors. 

Generic  characters.  —  Rays  five,  slender  and  tapering.  Disk  small, 
with  incipient  interbrachial  arcs. 

Abactinal  area  with  distinct  columns  of  radial  and  supramar- 
ginal plates,  between  which  are  inserted  rows  of  accessory  pieces, 
one  or  two  on  each  side  of  the  medial  columns.  In  mature  specimens 
the  radial  columns  are  less  prominent  proximally  than  distally. 
The  accessory  columns  proximally  may  also  have  here  and  there 
inserted  on  each  side  a  smaller  piece,  when  the  area  between  the 
supramarginals  has  not  only  three  or  five  columns  of  plates  but  also 
other  additional  small  plates.  The  inframarginal  columns  margin 
the  rays,  while  the  supramarginals  lie  somewhat  inside  and  above 
the  former.  Between  the  two  columns  of  marginals  there  may  be 
a  row  of  accessory  ambital  plates.  The  arrangement  of  the  plates 
of  the  disk  appears  to  be  as  follows:  In  the  center  there  is  a  small 
plate  around  which  is  a  first  ring  of  7  pieces,  followed  by  a  sec- 
ond ring  having  not  less  than  14  plates,  and  these  are  nearly  of 
one  size.  The  medial  ray  columns  terminate  on  the  disk  in  5 


REVISION    OF   PALEOZOIC   STELLEROIDEA.  75 

large  radial  plates,  but  inside  of  the  proximal  supramarginals  there 
is  no  basal  interradial  plate  as  in  Hudsonaster. 

Madreporite  unknown. 

Inframarginal  and  adambulacral  plates  as  in  Hudsonaster,  except- 
ing that  two  of  the  former  and  a  single  axillary  plate  are  in  each 
interbrachial  area.  Oral  armature  so  far  as  preserved  adambulacral, 
consisting  of  five  pairs  of  basal  adambulacrals. 

A  single,  pentagonal,  axillary  interbrachial  plate  is  present  in 
each  area,  orad  to  the  two  axile  inframarginal  plates. 

Ambulacral  grooves  deep  and  almost  closed  by  the  adambulacral 
columns.  Ambulacral  plates  carinate  and  apparently  one  to  each 
adambulacral  ossicle.  Their  relation  to  one  another  is  not  definitely 
determinable,  but  apparently  they  are  slightly  alternate  or  nearly 
opposite. 

Genoholotype. — Palxaster  shafferi  Hall. 

Distribution. — The  species  of  Mesopalseaster  are  restricted  to 
America  in  the  upper  portion  of  the  Ordovicic  and  the  lower  portion 
of  the  Siluric.  A  species  doubtfully  referred  to  this  genus  occurs 
hi  the  Lower  Devonic  of  Germany,  and  another  in  the  Upper  Devonic 
of  Maryland. 

The  following  are  the  species  of  Mesopalseaster: 

M.  shafferi  (Hall).  Middle  and  upper  beds  of  the  Cincinnatic 
series.  Possibly  also  in  the  Utica  formation  of  New  York. 

M.  intermedius,  new  species.     Maysville  formation. 

M.  finei  (Ulrich) .     Eden  formation. 

M.  (?)  lanceolatus,  new  species.     Utica  formation. 

M.  proavitus,  new  species.     Eden  formation. 

M.  (?)  wilberanus  (Meek  and  Worthen).     Richmond  series. 

M.  (?)  dubius  (Miller  and  Dyer).     Upper  Trenton. 

M .  (?)  antiquus  (Troost) .     Upper  Trenton. 

M.  (?)  parviusculus  (Billings).     Siluric  (Lower  Arisaig). 

M.   (?)  cataractensis,  new  species.     Siluric  (Cataract  formation). 

M.  granti  (Spencer).     Siluric  (Cataract  formation). 

M.  bellulus  (Billings).     Siluric  (Rochester  shale). 

M.  caractaci  (Gregory).     Caradoc  of  England. 

M.  (?)  acuminatus  (Simonovitsch) .     Lower  Devonic  of  Germany. 

M.  (?)  clarki  (Clarke  and  Swartz).  Upper  Devonic  (Jennings 
formation) . 

Remarks. — Mesopalseaster  apparently  developed  directly  out  of 
Hudsonaster  in  that  the  single  axillary  marginal  plates  are  in  the  former 
genus  in  nearly  all  the  species  pushed  inward  (interbrachial)  and 
their  former  place  occupied  by  the  proximal  plates  of  adjoining 
inframarginal  columns.  The  same  generic  feature  also  distinguishes 
Mesopalseaster  from  Palseaster.  Further,  in  Hudsonaster  there  are 
no  abactinal  accessory  ray  plates,  but  in  Mesopalseaster  one  or  two 
more  or  less  completely  developed  columns  are  inserted  on  each  side 


76  BULLETIN   88,  UNITED   STATES   NATIONAL   MUSEUM. 

of  the  radial  columns  or,  in  other  words,  between  the  radials  and 
supramarginals.  Between  the  inframarginal  and  supramarginal  plates 
in  Mesopalseaster  there  are  also  either  a  few  incipient  accessory  plates, 
which  in  young  specimens  are  wholly  absent,  or  there  is  a  complete 
column  of  these  ambital  plates.  The  accessory  and  axillary  inter- 
brachial  plates  are  additions  to  the  generic  structure  of  Hudsonaster 
and  Palseaster,  and  further  distinguish  Mesopalseaster  from  both. 
This  progression  toward  a  greater  number  of  columns  of  abactinal 
plates  attains  its  maximum  in  Promopalseaster  and  is  most  marked  in 
P.  magnificus,  which  has  not  less  than  28  columns  at  the  base  of  a 
ray  and  5  interbrachial  marginal  plates  in  each  interbrachial  area. 
The  ambulacral  furrows,  which  are  very  narrow  in  Hudsonaster,  are 
likewise  so  in  Mesopalseaster,  but  are  wide  in  Promopalseaster.  Spi- 
nosity,  which  is  practically  absent  abactinally  in  Hudsonaster,  is 
developed  in  Mesopalseaster  and  very  pronounced  in  some  forms  of 
Promopalseaster  (P.  spinulosus  and  P.  dyeri) .  This  is  apparently  also 
true  for  the  spines  of  the  actinal  area. 

The  youthful  plate  structure  of  recent  species  seems  to  be  retained 
to  maturity  in  Hudsonaster  and  somewhat  so  also  in  the  genotype 
of  Mesopaldeaster  but  in  Promopalseaster  the  central  area  of  the  disk 
is  occupied  by  numerous  very  small  plates  and  no  definite  arrange- 
ment is  discernible,  though  this  is  in  large  part  due  to  their  displace- 
ment through  fossilization.  However,  it  is  certain  that  the  basal 
radials  and  interradials  do  not  increase  nor  maintain  a  relative  size 
as  in  Hudsonaster  and  in  the  genotype  of  Mesopalseaster  (here 
radials  only),  but  must  have  diminished  to  that  of  the  accessory 
plates  from  which  they  are  now  not  distinguishable.  From  Hudson- 
aster  through  Mesopalseaster  into  Promopalseaster  the  animals  are 
constantly  increasing  in  size,  and  this  also  continues  in  the  species 
of  the  latter  genus,  attaining  culmination  in  P.  magnijicus  and  P.  dyeri. 

While  the  generic  abactinal  differences  between  Hudsonaster  and 
Mesopalseaster  are  easily  made  out,  this  is  not  so  readily  accom- 
plished between  the  latter  and  Promopalseaster.  All  of  the  abactinal 
generic  characters  of  Mesopalseaster  are  more  pronounced  in  Pro- 
mopalseaster excepting  that  in  the  former  the  ambital  accessory 
plates  are  almost  always  undeveloped  as  columns,  while  in  the  latter 
these  plates  are  always  well  developed  in  one  or  more  columns. 

When  the  actinal  area  is  shown,  Mesopalseaster  is  at  once  distin- 
guished from  Promopalseaster  in  that  it  has  but  one  axillary  inter- 
brachial plate  in  each  interbrachial  area,  while  the  latter  has  always 
two  or  more  up  to  five  ( =  interbrachial  marginals)  in  each  area. 

Devonaster  in  some  respects  is  closely  related  to  Mesopalseaster 
and  may  be  in  the  line  of  descent  from  the  latter.  However,  the  disk 
in  Mesopalseaster  has  far  fewer  abactinal  plates,  and  there  are  no 
distinct  interbrachial  arcs  with  numerous  small  accessory  plates 


REVISION    OF   PALEOZOIC    STELLEROIDEA.  77 

as  in  Devonaster.  The  pieces  of  the  radial  columns  in  Mesopalseaster 
adjoin  one  another  and  are  not  separated  by  intercalary  plates,  nor 
are  these  nearly  so  numerous  between  the  radial  and  supramarginal 
columns  as  in  Devonaster.  These  accessory  plates  in  Devonaster  are 
also  irregularly  disposed  and  not  in  columns  as  in  Mesopalseaster. 

The  name  Argaster  has  not  been  denned  nor  is  it  mentioned  in  such 
a  way  that  anyone  will  recognize  that  Hall  intended  it  for  a  new  genus 
or  subgenus.  In  addition,  its  genotype  (Asterias  antiqua  =  Mesopalse- 
aster (?)  antiguus)  is  a  poorly  known  species.  Under  these  circum- 
stances, and  the  additional  one  that  the  name  Argaster  never  has  had 
any  standing  as  a  genus,  it  should  not  now  be  rehabilitated  by 
paleontologists. 

MESOPALSEASTER  SHAFFER!  (Hall). 

Plate  8,  figs.  1,  2. 

Palseaster  sha/eri  HALL,  Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  1868,  p.  284; 
rev.  ed.,  1868=1870,  p.  326,  pi.  9,  fig.  1.— MEEK,  Geol.  Surv.  Ohio,  Pal.,  vol.  1, 
1873,  p.  66,  pi.  4,  fig.  1. 

Original  description. — "Body  of  about  medium  size  composed  of 
five  tapering,  acutely  pointed  rays,  which,  in  the  specimen  examined, 
measure  seven-eights  of  an  inch  from  the  center  of  the  disk  to  the 
extremity.  The  lower  side  of  the  ray  is  formed  of  two  ranges  of  plates 
bordering  the  ambulacral  groove.  The  marginal  range  consists  of 
moderately  convex  plates  which  gradually  decrease  in  size  from  the 
base  to  the  extremity  of  the  ray,  22  or  23  in  number  [not  more  than 
20  exist  in  any  ray  of  the  type-specimen],  besides  a  small  terminal 
one  at  the  angle  of  the  range;  each  plate  of  the  marginal  range  is 
marked  on  its  outer  surface  by  a  comparatively  large  cicatrix  for 
the  attachment  of  a  strong  spine.  The  inner  range  of  plates  (adam- 
bulacral)  are  somewhat  smaller,  about  the  same  in  number,  alternat- 
ing with  those  of  the  marginal  range;  the  basal  pair  (oral  plates) 
are  elongate-triangular,  and  slightly  constricted  near  the  middle. 
Ambulacral  a,reas  narrow,  composed  of  a  double  range  of  poral  plates, 
which  at  the  middle  of  the  ray  are  about  of  equal  length  and  breadth. 
Pores  not  observed.  [The  writer  could  not  make  out  these  plates  in 
the  type-specimen  and  believes  those  described  to  be  the  inner  sides 
of  the  actinal  plates.]  Upper  surface  of  the  ray  composed  of  three 
ranges  of  subnodose  plates,  the  outer  ranges  bearing  a  strong  spine 
on  each  plate;  the  central  range  apparently  destitute  of  spines.  No 
spines  have  been  observed,  but  the  plates  are  strongly  carinate  or 
pointed." 

Emended  description. — The  largest  specimen  in  the  Harris  collec- 
tion measures:  B,  =  19  mm.,  r  —  5.5  mm.,  R  =  3.5r.  Another  specimen 
of  the  same  collection:  R  =  16  mm.,  r  =  5  mm.,  R  =  3.1r.  The 
smallest  known  specimen  in  the  Vaupel  collection:  R  =  6.5  mm., 


78  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

r  =  2.5  mm.,  R  =  2.6r.  The  type-specimen,  which  is  the  largest  knowii 
example,  measures:  R  =  21  mm.,  r  =  6  mm.,  R  =  3.5r.  Width  of  ray 
at  base  in  various  mature  examples  5  mm.  to  7  mm. 

Rays  more  or  less  long,  slender,  abactinally  slightly  convex,  with 
marked  longitudinal  ridges,  actinally  flat  or  concave.  Disk  of  medium 
size,  abactinally  convex  and  without  interbrachial  arcs. 

Abactinal  area  of  rays  occupied  by  a  central  range  of  radial  plates, 
on  each  side  of  which  there  is  a  range  of  accessory  ossicles  which 
however  do  not  attain  the  distal  portion  of  the  rays.  In  mature 
rays  there  are  in  the  proximal  region  also  inserted  a  few  plates  on 
each  side  of  the  intercalary  columns.  Outside  of  the  latter  are 
the  ranges  of  well-defined  supramarginal  plates  which  slightly  overlap 
the  inframarginals.  The  marginal  and  radial  plates  are  most  promi- 
nent, and  all  are  highly  carinate  or  pointed.  There  is  a  single  large 
spine  on  the  apex  of  all  radial  and  accessory  plates  and  several 
smaller  ones  are  also  arranged  around  it.  The  supramarginal  plates 
have  numerous  granules  which  bore  articulating  spines.  The  plates 
of  the  disk  can  not  be  clearly  made  out,  but  in  a  small  specimen 
somewhat  distorted  there  appears  to  be  a  small  central  plate  sur- 
rounded by  a  first  ring  of  7  ossicles  followed  by  a  second  ring  of 
14  plates.  These  pieces  are  all  nearly  of  a  size.  The  medial  ray 
columns  terminate  in  5  large  basal  radial  plates,  while  inside  of 
the  proximal  inframarginals  there  is  no  large  interradial  plate  as  in 
Hudsonaster  incomptus. 

Ambital  area  very  illy  defined,  but  in  the  angles  between  the  large 
infra-  and  supramarginal  plates  there  are  here  and  there  inserted 
tiny  accessory  pieces.  In  a  young  individual  there  are  none  of  these 
accessory  plates. 

Madreporite  unknown. 

Inframarginal  plates  distinctly  granulated,  completely  inclosing 
all  other  abactinal  plates  and  common  to  both  the  abactinal  and 
actinal  areas.  In  mature  specimens  there  are  from  15  to  20  plates 
on  each  side  of  a  ray.  Laterally  each  plate  has  a  Well-marked  small 
pit,  probably  the  place  of  attachment  for  rather  strong  spines,  none 
of  which  however  have  been  observed. 

Interbrachial  areas  with  single,  hexagonal,  axillary  interbrachial 
plates. 

Adambulacral  plates  slightly  elongate-subquadrangular,  of  which 
there  are  from  18  to  20  on  each  side  of  a  ray;  distally  they  appear  to 
pass  over  and  to  cover  completely  on  the  actinal  side  the  inframar- 
ginal  plates.  Between  the  adambulacral  columns  there  is  a  more  or 
less  wide  ambulacral  furrow.  Each  adambulacral  plate  bears  on  its 
inner  edge  a  rather  thick  but  short,  slightly  striate  spine  and  several 
minute  ones.  Or  ad  to  each  axillary  interbrachial  there  is  a  pair  of 
prominent  elongate-triangular  adambulacral  plates  bearing  spines, 


REVISION   OF   PALEOZOIC    STELLEROIDEA.  79 

one  of  the  five  pairs  constituting  a  part  of  the  oral  armature.  In  other 
words,  the  adambulacral  columns  of  adjoining  rays  are  continued 
around  the  axillary  interbrachials  by  two  modified  plates. 

Ambulacral  grooves  deep,  nearly  closed  by  the  adambulacralia. 
Ambulacral  plates  not  well  shown  but  apparently  carinate,  one  to 
each  adambulacral  ossicle,  and  whether  alternate  or  opposite  can 
not  be  stated. 

Locality  and  formation. — -In  the  middle  and  .upper  stages  of  the 
Cincinnatic  group  (Ordovicic).  The  type-specimen  (No.  1195, 
Amer.  Mus.  Nat.  Hist.)  was  found  by  Mr.  D.  H.  Shaffer  at  Cincin- 
nati, Ohio,  probably  in  the  Maysville  formation.  Mr.  Vaupel  found 
a  young  individual  showing  the  abactinal  area  (No.  60605,  U.S.N.M.); 
another  young  one  was  secured  by  Mr.  Faber  (No.  9568,  University  of 
Chicago),  and  Mr.  George  Oeh  found  an  excellent  matured  individual 
preserving  the  actinal  area  (now  in  the  Yale  Museum),  all  from  the 
Maysville  formation  on  the  hills  back  of  Cincinnati.  Two  good  speci- 
mens and  another  small  poor  one  are  in  the  Harris  collection  of  the 
United  States  National  Museum  (No.  59391)  and  were  found  in  the 
Waynesville  division  of  the  Richmond  formation  near  Waynesville, 
Ohio. 

A  small  asterid  preserving  two  rays  and  a  portion  of  the  disk  "is  in 
the  United  States  National  Museum  collection  (No.  23540)  and  was 
found  by  Mr.  W.  P.  Rust  in  the  Utica  shales  one  and  a  half  miles  east 
of  Rome,  Oneida  County,  New  York.  It  is  associated  with  Trinucleus 
concentricus,  Dalmanella  testudinaria  multisecta,  and  other  species. 
The  abactinal  area  only  is  shown,  and  appears  to  be  that  of  Meso- 
palseaster  shafferi.  It  does  not  appear  to  be  a  Promopalseaster  because 
of  the  fewer  columns  of  abactinal  accessory  plates,  and  the  axillary 
structure  makes  it  almost  certain  that  there  is  here  but  a  single  axil- 
lary interbrachial  plate.  For  the  present  it  may  be  provisionally 
referred  to  this  species  and  attention  is  thus  directed  to  it  so  that  local 
collectors  may  be  on  the  lookout  for  other  material. 

Remarks. — This  species  has  actinally  much  the  appearance  of 
Hudsonaster  incomptus,  but  the  latter  is  at  once  distinguished  by  not 
having  the  five  axillary  interbrachial  plates  of  Mesopal&aster  shafferi. 
M.  (?)  parviusculus  (Billings)  is  smaller,  with  far  less  plates  in  all  the 
columns  than  in  M.  shafferi.  M.  (f)  parviusculus  and  M.  granti  differ 
also  abactinally  and  ambitally  in  the  better  developed  accessory 
plates. 

Cat.  Nos.  60605,  59391,  23540,  U.S.N.M. 

MESOPAL^ASTER  INTERMEDIUS,  new  species. 

Plate  9,  fig.  4. 

This  species  is  perplexing  in  its  generic  construction  because  of  its 
intermediate  or  transitional  characters  on  the  one  hand  (but  least) 
to  Hudsonaster,  and  on  the  other  (more  decidedly)  to  Mesopalxaster 

50601°— Bull.  §8—15 S 


80  BULLETIN    88,   UNITED   STATES   NATIONAL   MUSEUM. 

and  prophetic  of  Promopalseaster  in  the  conspicuous  ambulacral 
furrows. 

Rays  long  and  slender,  elongate-petaloid,  disk  small.  R  =  about 
14  mm.,  r=4  mm. 

The  interbrachial  areas  each  have  but  a  single,  large,  finely  granu- 
lated, axillary  plate  that  margins  the  axils,  and  in  this  agree  best  with 
Hudsonaster,  but  the  rest  of  the  known  skeleton  is  that  of  Meso- 
palaeaster.  In  the  former  genus  the  ambulacral  furrows  are  always 
very  narrow  and  the  ambulacralia  are  rarely  seen,  while  in  M. 
intermedius  the  furrows  are  wide  and  the  ossicles  are  rather  like  those 
of  Promopalseaster,  though  the  same  kind  of  ambulacralia  is  also 
known  in  Mesopalseaster.  Orad  to  the  axillary  plates  there  were  two 
small  oral  armature  pieces  that  belong  to  the  ad  ambulacral  columns. 
These  are  not  now  present  in  the  specimen,  but  the  distinct  and 
large  facet  of  the  proximal  side  of  the  axillaries  leaves  no  doubt  on 
this  construction. 

Inframarginal  columns  well-developed  proximally,  though  never 
very  prominent,  and  becoming  rapidly  smaller  distally.  The  four 
proximal  pieces  are  the  largest,  beyond  which  there  are  at  least 
14  other  ossicles,  and  all  are  closely  in  contact  and  alternate  with  the 
adambulacrals.  Another  feature  of  these  inframarginals  is  that  not 
more  than  six  can  be  seen  from  the  actinal  surface,  while  the  rest  pass 
on  to  the  sides  and  distally  even  somewhat  over  to  the  abactinal 
area.  All  of  the  plates  are  finely  granulated. 

Adambulacral  columns  the  most  prominent  of  the  actinal  skeleton, 
margining  the  distal  half  of  the  rays,  and  in  the  proximal  portion 
pass  more  and  more  inside  of  the  inframarginals,  diminishing  slowly 
in  size  and  finally  depressed  beneath  the  axillaries.  There  are  22 
plates  in  a  column,  all  more  coarsely  granulated  than  the  inframar- 
ginals, largest  and  most  transverse  near  mid-length  of  the  rays,  and 
all  are  drawn  out  inwardly  into  blunt  points  that  adjoin  the  high 
ridges  of  the  ambulacralia.  Therefore  the  adambulacral  and  the 
adjacent  ambulacral  columns  have  the  ossicles  directly  opposite  one 
another,  but  the  adjacent  ambulacral  rows  are  slightly  alternating. 

Ambulacral  furrows  conspicuous  and  wide,  widest  in  the  proximal 
third  but  converging  somewhat  quickly  hi  the  mouth  area  and  far 
more  gradually  distally.  Therefore  the  furrows  are  elongate-petaloid 
in  shape.  There  are  about  20  ambulacralia  in  a  column.  Proximally 
the  columns  unite  around  and  beneath  the  small  adambulacral  oral 
armature  pieces.  Ambulacralia  square  to  transversely  rectangular, 
each  with  a  high  L-shaped  crest  that  laterally  adjoins  the  points  of 
the  adambulacrals  and  medially  bends  orally.  Podial  openings  large 
between  the  corners  of  pairs  of  ambulacrals  and  adambulacrals. 
There  is  a  well-developed  groove  down  the  center  of  the  ambulacral 
furrows. 


REVISION   OF  PALEOZOIC   STELLEEOIDEA.  81 

Abactinal  area  unknown,  but  probably  that  of  Mesopalseaster  and 
nearest  to  M.  shafferi. 

Formation  and  locality. — The  holotype  was  found  by  Faber  in  the 
Maysville  formation  at  Cincinnati,  Ohio,  about  350  feet  above  the 
Ohio  River.  The  type  is  in  the  University  of  Chicago  Museum 
(No.  9575). 

Remarks. — This  interesting  species  need  be  compared  only  with  M. 
shafferi.  It  differs  in  having  the  axillaries  in  the  axils  of  the  rays 
and  not  inside  the  basal  inframarginals  as  in  the  latter  form.  Then 
in  M.  shafferi  the  inframarginals  are  actinal  in  position  throughout, 
while  in  M.  intermedius  they  are  more  on  the  sides.  Further,  in  the 
new  form  the  ambulacral  furrows  are  well  developed  with  large 
ambulacralia,  while  in  M.  shafferi  the  furrows  are  narrow  and  the 
ossicles  rarely  seen. 

MESOPAL^SASTER  FINEI  (Ulrich). 
Plate  7,  fig.  5;  plate  9,  fig.  5. 

Palseaster  finei  ULRICH,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  2,  1879,  p.  19,  pi. 
7,  figs.  15-156. 

Original  description. — "Small;  rays  five,  of  medium  length,  rather 
broad,  pointed  and  narrower  where  they  are  attached  to  the  much 
contracted  body  [probably  due  to  distortion],  than  they  are  about 
the  center  of  their  length. 

"  Dorsal  side  of  rays  composed  of  four  [about  seven,  the  supra-  and 
inframarginals,  radials,  and  two  intercalary  columns]  rows  of  pieces, 
that  are  quite  close  [?]  fitting,  as  wide  as  long,  from  12  to  14  in  each 
row,  and  increase  in  size  inward  to  the  disk,  which  is  composed  of 
irregularly  shaped  and  prominent  pieces  some  of  which  are  smaller 
and  others  larger  than  those  composing  the  rays;  the  pieces  in  the 
marginal  rows  [four  columns  infra-  and  supramarginals]  are  more 
prominent  than  the  two  [there  are  three,  radials  and  two  intercalary] 
rows  between  them,  and  have  a  small  pit  in  the  center,  probably  for 
the  articulation  of  a  spine  [all  of  the  plates  originally  bore  several 
short  slender  spines].  Madreporiform  body  rather  small,  circular, 
very  prominent,  and  marked  by  strong  striae,  which  become  more 
numerous  toward  the  margin  by  intercalation. 

"Marginal  [inframarginal]  pieces  on  the  ventral  surface,  convex, 
quite  as  long  as  wide,  and  numbering  in  different  specimens  on  each 
side  from  11  to  12  [probably  not  more  than  8  or  9];  the  piece  at  the 
junction  of  the  rays  is  three  times  as  large  as  any  other  of  the  series, 
subcircular  and  very  convex.  [It  appears  that  this  large  plate  is  an 
axillary  interbrachial  since  upon  it  proximally  rest  two  basal  plates 
of  the  inframarginal  series.] 


82  BULLETIN"   88,   UNITED   STATES   NATIONAL   MUSEUM. 

"  Adambulacral  plates  more  prominent  [less  prominent  than  the 
inframarginal  plates],  slightly  wider  than  long,  and  numbering,  on 
each  side,  from  9  to  10  [probably  not  less  than  16  in  each  column]. 
Ambulacral  pieces  a  little  wider  than  long,  not  alternating  with  the 
adambulacral  plates,  and  each  provided  with  a  rather  sharp  ridge 
across  most  of  its  width. 

"There  are  10  oral  plates  [oral  armature]  formed  by  the  junction 
of  the  adambulacral  rows,  which  in  form  and  size  are  scarcely  dis- 
tinguishable from  the  other  plates  of  those  series. 

"  Greatest  breadth  measuring  between  the  opposite  extremities  of 
the  rays;  0.7  inch;  breadth  of  rays  at  their  inner  ends,  0.1  inch; 
length  of  same,  0.3  inch;  diameter  of  madreporiform  piece,  0.02 
inch." 

Formation  and  locality. — This  small  species  appears  to  be  common 
at  a  very  restricted  horizon  near  the  base  of  the  Eden  formation 
(Fulton  beds),  exposed  at  low  water  mark  in  the  Ohio  Biver  in  the 
eastern  portion  of  Cincinnati,  Ohio. 

Remarks. — Not  one  of  the  twenty  examples  seen  is  well  preserved 
and  all  the  plates  are  more  or  less  separated.  The  general  structure 
seems  to  be  that  of  Mesopalseaster.  The  composition  of  the  axillary 
area  is  not  positively  ascertainable  but  one  specimen  shows  what 
appears  to  be  a  large  axillary  interbrachial  plate  (see  pi.  7,  fig.  5), 
distally  surmounted  by  two  somewhat  smaller  inframarginals.  This 
is  probably  the  true  structure  since  it  is  so  in  all  the  smaller  Meso- 
palseasters,  as  M.  lanceolatus,  M.  parviusculus,  M.  granti,  and  M. 
proavitus. 

The  differences  between  M.  finei  and  M.  proavitus  are  not  great. 
The  former  is  a  smaller  species  with  less  plates  in  all  of  the  ranges, 
more  prominent  axillary  inframarginal  and  axillary  interbrachial 
plates,  and  is  also  found  at  a  lower  geological  horizon.  M.  finei 
differs  from  the  small  species  M.  parviusculus  of  the  earliest  Siluric 
in  having  more  plates  in  all  of  the  columns.  M.  granti  is  a  larger 
species  and  with  smaller  and  more  numerous  plates  than  in  M.  finei. 
M.  lanceolatus  is  probably  the  most  closely  related  to  M.  Jinei  but  is 
distinguished  abactinally  by  the  diagonal  arrangement  of  the  plates 
on  each  side  of  the  radial  columns. 

Cat.  No.  60604,  U.S.N.M. 

MESOPALJEASTER(P)  LANCEOLATUS,  new  species. 

Plate  4,  fig.  3. 

Measurements:  R  =  4.5  mm.,  r=1.3  mm.,  R  =  3r). 

Rays  short,  stout,  distinctly  lanceolate  actinally  and  rapidly  ta- 
pering abactuially.  Disk  comparatively  large,  abactinally  convex. 
Interbrachial  arcs  distinct  but  small. 

Abactuially  the  disk  has  a  ring  of  large,  strongly  stellate  plates 
which  are  the  basal  plates  of  the  radial  and  supramarginal  columns. 


REVISION   OF   PALEOZOIC    STELLEEOIDEA.  83 

Inside  the  ring  the  plates  can  not  be  made  out,  due  to  the  small  size 
of  the  specimen.  Rays  each  with  a  column  of  radials  and  two  supra- 
marginals  between  which  are  inserted  columns  of  diagonally  arranged 
accessory  plates.  A  few  ambital  accessory  plates  are  probably  also 
present.  The  arrangement  of  the  ossicles  on  the  abactinal  areas  of 
the  rays  is  like  that  hi  Promopalxaster  magnificus. 

Madreporite  small,  subconical,  situated  near  the  edge  of  the  disk, 
depressed  between  adjoining  basal  plates  and  marked  by  10  or  11 
sharp,  somewhat  spirally  arranged  ridges. 

Inframarginal  plates  large,  about  six  in  each  column  proximal  to 
the  very  large  single  axillary  interbrachial  plate.  These  columns  in 
the  distal  half  can  not  be  seen  actinally  as  they  pass  over  on  the  dorsal 
side. 

Axillary  interbrachial  plates  large,  one  in  each  axil,  and  not  com- 
pletely inclosed  outwardly  by  the  basal  inframarginals.  In  this 
character  the  form  is  still  in  the  Hudsonaster  stage. 

Adambulacral  plates  small,  subquadrangular,  with  16  plates  in  each 
column.  The  plates  of  the  adambulacral  oral  armature  are  larger 
and  wedge-shaped,  and  are  situated  directly  inside  of  the  axillary 
interbrachial  plates. 

Ambulacra!  plates  one  to  each  adambulacral,  apparently  opposite 
and  with  proximally  converging  ridges.  Podial  openings  apparently 
along  the  outer  edge  between  the  sutures  of  adjoining  plates. 

Formation  and  locality. — Two  specimens  were  found  by  the  late 
Prof.  Charles  E.  Beecher  near  Rome,  New  York,  in  the  Triarthrus 
bed  of  the  Utica  formation  that  preserves  the  entire  ventral  anatomy 
of  these  trilobites.  The  co types  are  in  the  Museum  of  Yale  University. 
Mr.  W.  S.  Valiant  in  a  letter  states  that  they  are  common  in  a  layer 
2  to  3  inches  above  the  Triarthrus  bed. 

Remarks. — This  species  is  most  closely  related  to  M.  finei,  from 
which  it  is  readily  distinguished  abactinally.  Here  there  are  more 
and  smaller  plates  than  In  M.  lanceolatus,  the  interpolated  plates  are 
arranged  diagonally  and  not  radially  as  in  M.  finei,  while  the  basal 
plates  of  the  former  are  apparently  much  larger  and  are  strongly  stel- 
late. Actinally  there  are  in  M.  lanceolatus  more  adambulacral  plates 
in  each  column,  although  the  specimens  are  only  half  the  size  of  M. 
finei. 

MESOPAL^ASTER  PROAVITITS,  new  species. 

R=18  mm.,  r^about  4.5  mm.  The  specimens  are  distorted,  however, 
and  no  exact  measurements  can  be  given. 

On  the  distal  abactinal  portion  of  the  rays  the  infra-  and  supra- 
marginal  and  radial  plates  closely  adjoin.  Proximally,  however, 
between  the  two  marginal  series  there  is  inserted  a  column  of  inter- 
calary plates  gradually  increasing  in  size  and  two  other  similar  rows 
of  plates  are  placed  between  the  supramarginal  and  radial  columns. 


84  BULLETIN    88,   UNITED   STATES    NATIONAL    MUSEUM. 

There  are  therefore  at  the  base  of  the  rays  no  less  than  11  columns 
of  plates.  The  radial  columns  proximally  have  a  tendency  to  become 
less  distinct  and  indistinguishable  from  the  accessory  pieces.  The 
plates  in  general  are  highly  convex,  granular  and  abundantly  spine- 
bearing.  There  are  not  less  than  20  plates  in  each  supramarginal 
series. 

Madreporite  highly  convex,  broadly  oval  in  outline  and  radially 
striated. 

Inframarginal  plates  finely  granular,  highly  convex,  subquad- 
rangular  in  outline  and  increasing  in  size  slowly  proximally.  About 
23  in  each  column. 

Adambulacral  plates  like  the  inframarginals  but  not  increasing 
much  in  size  proximally,  with  about  29  in  each  column.  As  in  other 
species  of  this  genus,  each  plate  bears  three  prominent  spines,  two 
laterally  and  one  ambulacrally. 

Ambulacral  plates  one  to  each  adambulacral  plate,  and  with  a 
sharp  ridge  which  medially  bends  abruptly  orally.  Podial  openings 
as  in  other  forms  of  Mesopalseaster. 

Interbrachial  areas  occupied  by  single  axillary  interbrachial  plates 
upon  each  of  which  rest  proximally  two  axillary  inframarginals. 

The  specimens  are  not  figured,  as  an  illustration  can  not  readily 
be  made. 

Formation  and  locality. — Three  more  or  less  entire  specimens  and 
fragments  of  four  rays  were  found  by  Dr.  E.  O.  Ulrich  in  the  Eden 
shale  exposed  back  of  Covington,  Kentucky,  at  an  horizon  about 
100  feet  above  low  water  in  the  Ohio  River.  All  the  specimens  a^e 
now  in  the  Herzer  collection,  a  part  of  the  late  Prof.  James  HalFs 
private  collection,  recently  purchased  by  the  University  of  Chicago. 

Remarks. —  M.  proavitus  and  M.  granti  are  closely  related,  since 
both  have  11  columns  of  abactinal  plates,  including  the  marginals, 
and  they  are  nearly  alike  actinally.  However,  the  former  is  twice  as 
large  and  appears  to  have  more  conspicuous  radial  and  supramarginal 
columns  than  the  latter.  These  differences  and  the  further  fact  that 
one  occurs  in  the  Utica  and  the  other  in  the  earliest  Siluric  will  serve 
to  distinguish  the  two  species  for  the  present.  M.  proavitus  may 
prove  to  bo  identical  with  M.  (?)  wilberanus,  which  see  for  further 
remarks. 

MESOPAL^ASTER  (?)  WILBERANUS  (Meek  and  Worthen). 

Petraster  wilberianus  MEEK  and  WORTHEN,  Proc.  Acad.  Nat.  Sci.,  Philadelphia, 

for  1861,  vol.  13,  1862,  p.  142. 
Palseaster  wilberanus  HALL,  Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  1868, 

p.  285;  rev.  ed.,  1868=1870,  p.  328. 

Original  description. — "This  beautiful  starfish  resembles  rather 
closely  Petraster  rigidus  of  Billings,1  but  is  smaller,  and  has  more 

1  Decade  3,  Org.  Rem.  Canada,  pi.  9,  fig.  3o. 


REVISION    OF   PALEOZOIC    STELLEROIDEA.  85 

slender  rays,  with  more  angular  spaces  between.  It  also  differs  in 
having  but  two  ranges  of  plates  on  each  side  of  the  ambulacral 
grooves,  on  the  under  side,  instead  of  three.  These  pieces  are  about 
of  the  same  size  in  each  row,  and  sometimes  appear  to  alternate; 
they  are  all  rather  prominent,  and  those  of  the  outer  range  project 
a  little  laterally  in  the  form  of  small  nodes.  Toward  the  outer 
extremities  of  the  rays,  however,  the  lateral  ranges  are  contracted 
behind  the  others,  so  as  to  be  scarcely  visible  from  below.  About  23 
of  these  pieces  may  be  counted  on  each  side  of  the  ambulacral  furrow 
in  each  ray.  The  ambulacral  furrows  are  very  narrow,  and  indeed 
seem  to  be  closed  toward  the  extremities  of  the  rays,  by  the  gradual 
approximation  of  the  inner  rows  of  pieces  on  each  side,  which  alter- 
nate and  appear  to  fit  together. 

"Our  specimen  only  shows  the  under  side,  but  along  the  outer 
margins  of  two  of  the  rays,  there  is  some  appearance  either  of  the 
overlapping  of  some  of  the  dorsal  parts  by  pressure,  or  of  a  slightly 
developed  disk.  This  part  does  not  seem  to  have  any  distinct  range 
of  marginal  plates,  but  appears  to  be  made  up  of  small  pieces,  covered 
with  granules,  or  bases  of  small  spines. 

"We  take  pleasure  in  dedicating  this  interesting  species  to 
Prof.  C.  D.  Wilber,  of  the  Illinois  State  Normal  School,  to  whom  we 
are  indebted  for  the  use  of  the  only  specimen  we  have  seen. 

"Greatest  diameter  about  1  inch;  smaller  diameter  0.33  inch. 

"Locality  and  position. — Oswego,  Kendall  County,  Illinois,  in  rocks 
of  the  age  of  the  Trenton  or  Hudson  River  Group  of  the  New  York 
series."  Probably  equivalent  to  the  Richmond  beds  of  the  highest 
Ordovicic.  The  whereabouts  of  the  type-specimen  is  not  known. 

Remarks. — Hall  pointed  out  that  this  species  is  not  a  Petraster 
because  P.  wilberanus  has  but  two  columns  of  plates  on  each  side  of 
the  ambulacral  groove,  while  Petraster  has  in  addition  "a  few  disk 
plates  on  the  ventral  side."  He  therefore  referred  it  to  Pal&aster. 
However,  Meek  and  Worthen  describe  the  abactinal  area  as  having 
no  "  distinct  range  of  marginal  plates,  but  appears  to  be  made  up  of 
small  pieces,  covered  with  granules,  or  bases  of  small  spines."  The 
characters  as  far  as  mentioned  appear  to  be  those  of  Mesopal&aster. 
Should  there  prove  to  be  in  P.  wilberanus  single  axillary  interbrachial 
plates,  then  all  of  the  characters  will  be  in  harmony  with  Mesopalse- 
aster  and  M.  proavitus  may  prove  to  be  a  synonym  of  it.  This 
can  not  be  proven  at  present  since  we  have  not  been  able  to  locate 
the  type-specimen. 

MESOPAL^ASTER  (?)  DUBITJS  (Miller  and  Dyer). 

Palseaster  dubius  MILLER  and  DYER,  Cont.  to  Pal.,  No.  2,  1878,  p.  5,  pi.  4,  fig.  8. 

Original  description. — "Pentagonal;  rays  longer  than  the  diameter 
of  the  body,  and  uniformly  tapering.  The  ambulacral  groove  is 
sharply  angular  in  the  middle,  formed  by  two  series  of  plates  having 


86  BULLETIN   88,  UNITED   STATES   NATIONAL  MUSEUM. 

their  ends  together  in  such  manner  as  to  make  an  angular  gutter 
[the  plates  of  adjoining  columns  are  arranged  practically  opposite]. 
The  length  of  these  plates  is  three  times  as  great  as  the  diameter. 
The  plates  are  placed  with  the  length  across  the  rays.  There  are 
15  plates  on  each  side  of  the  groove  in  each  ray,  in  the  length  of  one 
quarter  of  an  inch  [this  is  an  error  as  there  are  about  20  plates  in  a 
column].  The  diameter  of  the  body  is  three-tenths  of  an  inch. 

"This  species  is  founded  upon  a  single  specimen,  in  Mr.  Dyer's 
collection,  which  shows  only  part  of  the  ventral  side.  The  ends  of 
the  rays  [most  of  the  adambulacrals]  and  marginal  plates  arc  destroyed 
[each  axillary  area  appears  to  bear  one  axillary  interbrachial  plate]. 
The  parts  preserved  seem  to  distinguish  it  from  any  species  hitherto 
described." 

Formation  and  locality. — In  the  original  description  the  locality 
is  given  as  Cincinnati,  Ohio,  but  the  character  of  the  rock  shows  that 
it  is  from  the  uppermost  portion  of  the  Trenton  limestone,  probably 
opposite  Cincinnati,  in  the  river  quarries  at  Ludlow,  Kentucky. 
The  type  (No.  25)  is  in  the  Museum  of  Comparative  Zoology,  Harvard 
University. 

Remarks. — This  specimen  preserves  well  the  very  wide  ambulacrals 
but  almost  no  other  plates.  The  adambulacrals  are  nearly  all  removed 
and  but  very  little  is  to  be  seen  of  the  marginals.  In  three  of  the 
axillary  areas  there  are  single  interbrachial  plates,  one  of  the  essential 
features  of  Mesopalseaster.  It  is  referred  to  this  genus  provisionally, 
as  nothing  is  known  of  the  abactinal  side. 

MESOPAL^ASTER  (?)  ANTIQUTJS  (Troost). 

Asterias  antiqua  TROOST  (not  Hisinger  1837),  Trans.  Geol.  Soc.  Penn.,  vol.  1, 1835, 
p.  232,  pi.  10,  fig.  9;  Proc.  Amer.  Assoc.  Adv.  Sci.,  vol.  2, 1850,  p.  59  (cat.  name). 

Petraster  (?)  antiqua  SHUMARD,  Trans.  St.  Louis  Acad.  Sci.,  vol.  2,  1866,  p.  386 
(catalogue  name). 

Palxaster  (Argaster)  antiqua  HALL,  Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist., 
1868,  p.  287;  rev.  ed.,  1868=1870,  p.  329. 

Palxaster  antiquus  MILLER,  N.  Amer.  Geol.  Pal.,  1889,  p.  265  (cat.  name). 

Argaster  antiqua  GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6,  1899,  p.  345  (gen.  ref.). 

Pal&aster  antiqua  WOOD,  Bull.  U.  S.  Nat.  Mus.,  No.  64,  1909,  p.  105,  pi.  8,  fig.  1. 

Although  this  is  the  first  recorded  American  fossil  starfish,  very 
little  is  known  about  it  and  that  little  is  mostly  of  a  misleading  nature. 
The  specimen  lies  on  a  limestone  slab  and  is  very  badly  weather- 
worn or  it  may  have  been  treated  with  hydrochloric  acid  so  that  now 
it  is  nothing  more  than  a  polished  section  of  a  starfish.  An  illustra- 
tion that  will  show  its  actual  characters  can  not  be  made. 

Professor  Hall  errs  in  stating  that  Asterias  antiqua  has  "ambu- 
lacral  grooves  occupied  by  a  single  row  of  subquadrate  ossicula,  which 
extend  across  and  alternate  with  the  adambulacral  plates  of  each  mar- 
gin. *  *  *  It  is  possible  that  this  character  may  prove  to  be 
of  generic  importance."  It  may  have  been  this  character  on  which 


REVISION"   OF  PALEOZOIC   STELLEROIDEA.  87 

Hall  thought  of  basing  the  genus  Argaster,  but  he  does  not  character- 
ize it  nor  even  mention  that  the  name  in  parenthesis  is  intended 
as  a  new  term  with  Asterias  antiqua  Troost  as  the  genotype.  This 
species,  like  all  other  Paleozoic  starfishes,  has  double  columns  of 
ambulacral  plates.  This  the  specimen  clearly  demonstrates  on 
the  edge  of  the  slab  where  the  distal  parts  of  the  rays  are  broken 
away.  Argaster  should  therefore  be  regarded  as  a  nomen  nudum,  and 
should  A.  antiqua  prove  to  be  a  Mesopal&aster,  it  should  not  be 
made  to  displace  this  genus. 

Asterias  antiqua  has  about  15  inframarginal  plates  in  each  column 
and  about  32  in  each  adambulacral  column.  Two  of  the  latter  plates 
meet  as  usual  in  a  pair  of  triangular  oral  armature  pieces. 

Each  axil  is  occupied  by  two  large,  quadrangular,  basa]  inframar- 
marginal  plates.  Between  these  proximally  there  is  a  large,  widely 
triangular,  interbrachial  plate  the  apex  of  which  may  or  may  not 
attain  the  margin.  Proximal  to  each  axillary  interbrachial  plate 
and  between  the  four  or  five  pairs  of  axillary  adambulacral  plates, 
there  is  in  the  specimen  an  open  space  in  each  of  the  five  areas. 
What  additional  plates,  if  any,  occupied  this  area  is  not  de terminable. 
It  may  be  that  the  axillary  interbrachial  plates  occupied  the  entire 
interbrachial  areas  and  that  the  present  hiatus  is  due  to  the  worn 
condition  of  the  specimen.  This  appears  to  be  the  most  natural 
interpretation  as  it  is  the  normal  inter brachial  structure  of  Mesopa- 
Iseaster.  In  Promopalseaster  there  are  always  two,  three,  five,  or  seven 
interbrachial  marginal  plates  hi  each  area,  a  fact  which  excludes  Aste- 
rias antiqua  from  that  genus. 

The  abactinal  area  is  not  visible,  but  many  of  these  plates  are 
squeezed  beyond  the  inframarginals,  showing  the  presence  of  num- 
erous small  plates  recalling  Mesopalseaster  and  Promopalseaster. 

Formation  and  locality. — Troost's  label  reads:  " Lower  limestone 
on  Harpeth  Kiver,  Davidson  County,  Tennessee."  His  manuscript 
reads:  "It  was  found  *  *  *  on  Harpeth  Kiver,  Davidson 
County,  Tennessee.  Associated  with  Spirifer  lynx  [PlatystropJiia 
l}iforata]}  Cyathop7i[y]Ua  [  — Streptelasma]}  Orthis  [testudinaria],  etc." 
This  is  apparently  the  same  horizon  as  that  about  the  city  reservoir 
in  Nashville,  which  is  now  regarded  as  of  Upper  Trenton  (Catheys) 
age.  The  specimen  is  in  the  United  States  National  Museum. 

Cat.  No.  39914,  U.S.N.M. 

MESOPAL^EASTER(?)  PARVIUSCULUS  (Billings). 

Plate  9,  fig.  1. 

Palseaster  parviusculus  BILLINGS,  Canadian  Nat.  and  Geol.,  vol.  5,  1860,  p.  69, 
figure. — DAWSON,  Acadian  Geology,  2d  ed.,  1868,  p.  594,  fig.  197. — HUDSON, 
Bull.  N.  Y.  State  Mus.,  No.  164,  1913,  pis.  1-4. 

Original  description. — ' l  The  specimen  is  about  six  lines  in  diameter. 
The  rays  are  two  lines  in  length  and  one  and  a  half  in  width  at  the 


88  BULLETIN   88,  UNITED   STATES   NATIONAL  MUSEUM. 

base,  tapering  at  an  angle  of  a  little  less  than  45°.  The  five  oral 
plates  are  subpentagonal,  about  half  a  line  in  width.  The  first 
adambulacral  plates  of  each  pair  of  adjacent  rays  are  in  contact 
with  each  other  outside  of  the  oral  plates,  and  not  completely  sep- 
arated as  they  are  in  P.  niagarensis.  There  are  six  or  seven  adam- 
bulacral plates  on  each  side  of  the  ambulacral  groove  in  each  ray, 
and  they  gradually  decrease  in  size  from  the  oral  plate  outward  to 
the  point  of  the  ray.  The  width  of  the  ambulacral  groove  is  equal 
to  one-third  the  width  of  the  ray  and  consequently  the  adambu- 
lacral rows  of  plates  are  also  each  equal  to  one-third  the  whole  width 
of  the  ray.  In  each  groove  there  are  two  rows  of  small  and  appar- 
ently nearly  square  ambulacral  plates,  12  or  14  in  each  row,  and  they 
seem  to  be  continued  round  on  the  inner  margin  of  the  oral  plates; 
the  mouth  is  about  one  line  wide." 

Emended  description. — Measurements:  R  =  6  mm.,  r  =  2.5  mm., 
R  =  2.4r.  Width  of  ray  at  base  3  mm. 

Rays  short,  stout,  tapering  rapidly.  Disk  comparatively  large, 
and  without  interbrachial  arcs. 

Abactinal  area  unknown. 

Inframarginal  plates  at  the  base  of  the  rays  very  large  and  thick, 
highly  convex,  duninishing  rapidly  distally,  usually  quadrangular 
in  form  and  seven  on  each  side  of  a  ray. 

Just  within  each  axil,  inside  of  the  basal  inframarginals,  there  is 
a  single,  large,  very  convex,  pentagonal,  axillary  interbrachial  plate. 

Adambulacral  plates  gradually  sinking  below  the  inframarginals 
proximally,  convex  and  quadrangular  in  form.  There  are  13  plates 
in  each  column  adjoining  the  very  narrow  ambulacral  furrow,  or 
nearly  two  plates  to  each  inframarginal  ossicle.  Two  of  these 
plates  (oral  armature)  are  situated  in  front  of  each  axillary  inter- 
brachial, uniting  the  adambulacral  columns  of  adjoining  rays. 

Ambulacral  plates  unknown. 

Locality  and  formation. — The  type-specimen,  a  natural  mold,  was 
found  by  Rev.  D.  Honeyman  in  the  Lower  Arisaig  of  the  Siluric 
(  =  Clinton)  rocks  at  Arisaig,  Nova  Scotia.  The  holotype  is  in 
Redpath  Museum  of  McGill  University,  Montreal,  Canada,  and  the 
illustration  is  taken  from  a  gutta-percha  squeeze  kindly  made  for 
the  United  States  National  Museum  by  Sir  William  Dawson. 

Remarks. — The  general  actinal  appearance  of  this  little  asterid 
reminds  one  much  of  Palseaster  and  Hudsonaster.  It  differs,  however, 
at  once  in  a  little  detail  of  considerable  importance,  in  that  each 
axillary  area  has  three  plates,  while  in  Palseaster  and  Hudsonaster 
there  is  but  one.  In  other  words,  the  large  axillary  plate  of  those 
genera  has  in  M.  (?)  parviusculus  been  pushed  orally  and  is  here  an 
interbrachial  plate,  while  the  axils  of  the  rays  are  occupied  by  two 
basal  inframarginal  plates.  For  further  remarks  on  this  species  see 
M.  granti  (Spencer). 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  89 

So  long  as  the  abactinal  area  of  M.  (?)  parviusculus  remains 
unknown  its  generic  position  will  be  doubtful.  For  the  present  its 
relations  appear  to  be  nearest  to  Mesopalseaster  and  to  M.  (?)  cata- 
ractensis. 

Cat.  No.  60620,  U.S.N.M. 

MESOPAL.EASTER  (?)  CATARACTENSIS,  new  species. 
Plate  9,  fig.  2. 

The  specimen  of  this  species  has  been  confused  with  M.  (?)  gmnti, 
from  which  it  differs  in  being  smaller  and  in  having  far  fewer  plates 
in  the  columns.  The  actinal  side  of  M.  (f)  cataractensis  alone  is 
known,  while  of  M.  (?)  granti  only  the  abactinal,  but  even  so  the 
above  comparison  can  still  be  made  because  the  size  of  plates  is 
relatively  about  the  same  in  species  of  Mesopalseaster. 

Measurements:  K  =  9  mm.,  r=3  mm.,  R  =  3r. 

The  species  is  most  closely  related  to  M.  (f)  parviusculus,  but 
differs  in  being  larger  with  more  plates  in  the  columns.  Of  M.  (?) 
cataractensis  only  the  actinal  side  is  known,  with  12  to  13  plates 
in  each  inframarginal  column  (7  in  M.  (?)  parviusculus)  and 
about  19  in  the  adambulacrals  (13  in  M.  (?)  parviusculus).  Then 
the  inframarginals  increase  very  rapidly  in  size  proximally,  while 
in  M.  (?)  cataractensis  there  is  but  little  enlargement. 

A  single  small,  pentagonal,  axillary  interbrachial  plate  occurs 
in  each  area  immediately  beneath  the  basal  inframarginals.  These 
are  much  smaller  relatively  than  those  in  M,  (?)  parviusculus. 

Ambulacral  plates  unknown.  Ambulacral  furrows  deep,  nearly 
completely  closed  by  the  adambulacral  columns. 

Formation  and  locality.— in  the  base  of  the  Siluric  (Cataract  for- 
mation) at  Hamilton,  Ontario.  The  holotype  was  found  by  Mr. 
Elliott  near  the  city  reservoir  and  is  in  the  collection  of  the  Hamilton 
Natural  History  Society.  It  was  loaned  to  the  writer  by  the  late 
Col.  Charles  Coote  Grant. 

MESOPALJEASTER  GRANTI  (Spencer). 
Plate  9,  fig.  3. 

Palseaster  granti  SPENCER,  Bull.  Mus.  Univ.  Missouri,  No.  1,  1884,  p.  53,  pi.  7, 
fig.  1. 

Original  description. — "Body  stellate  and  small  with  short  arms, 
about  2  centimeters  across;  disk  less  than  1  centimeter  wide,  and 
apparently  formed  by  the  junction  of  the  rays;  rays  5  millimeters 
wide  at  base,  tapering  slowly,  and  terminating  in  rounded  extrem- 
ities, at  about  8  millimeters  from  junction  of  their  base  with  the 
disk;  upper  surface  of  rays  composed  of  5  [not  less  than  9  in  mature 
specimens  at  mid-length  of  rays]  ranges  of  highly  convex  or  tuberculi- 
form  plates  (the  marginal  [supramarginal]  and  ventral  [inframarginal] 


90  BULLETIN   88,   UNITED   STATES   NATIONAL  MUSEUM. 

rows  being  the  most  conspicuous)  and  separated  from  each  other  by 
minute  plates  (becoming  fewer  on  approaching  the  extremities  of 
the  rays) . 

"The  ellipsoid  [supra]  marginal  tuberculiform  plates  number 
about  12  [20  in  mature  examples]  for  each  complete  side  of  the  rays, 
and  the  central  range  [radial]  is  composed  of  a  similar  number,  but 
in  form  these  plates  are  more  circular.  The  disk  between  the  ter- 
minal central  [radial]  row  of  plates  of  the  rays  is  crushed  and  struct- 
ureless, except  a  slight  elevation  in  the  center.  The  terminal  [proxi- 
mal] plates  of  the  marginal  series  are  larger  than  the  others  of  the 
range.  The  madreporiform  tubercle  is  of  a  spherical  form  and  rela- 
tively large,  being  nearly  2  millimeters  in  diameter,  and  is  situated 
at  the  axil  of  two  rays.  Both  the  tuberculiform  plates  and  the 
madreporiform  tubercle  have  a  granulated  surface. 

"The  ventral  side  is  unknown. 

Emended  description. — A  mature  specimen  measures:  R=16  mm., 
r=5  mm.;  R  =  3.3r. 

Rays  short,  stout,  tapering  rapidly,  and  with  very  small  inter- 
brachial  arcs. 

Abactinal  area  of  disk  unknown.  Along  the  center  of  each  ray 
there  is  a  radial  column  of  small,  highly  convex  plates  bounded  on 
each  side,  at  about  the  mid-length  of  the  rays,  by  two  columns  of 
smaller,  strongly  tumid,  accessory  plates.  The  radial  column  is, 
however,  not  distinctly  differentiated  from  those  adjoining.  Out- 
side of  these  are  the  supramarginal  columns,  each  with  about  20 
plates  which  are  larger  and  more  easily  distinguished  than  the  radial 
plates.  Dis tally  the  rays  have  only  the  ossicles  of  the  infra-  and 
supramarginal  and  radial  columns,  with  none  of  the  accessory  plates 
as  yet  developed. 

Ambital  area  with  one  column  of  very  small  accessory  plates 
like  the  marginal  plates  on  each  side  of  them.  These  accessory  pieces 
disappear  before  attaining  the  apex  of  the  rays. 

Madreporite  spherical  in  form  and  relatively  large,  nearly  2  milli- 
meters in  diameter,  and  situated  at  the  .axil  of  two  rays  between 
two  adjoining  supramarginal  columns. 

Formation  and  locality. — From  the  Cataract  formation,  the  basal 
deposits  of  the  Siluric  system,  near  the  reservoir  in  the  city  of 
Hamilton,  Ontario.  Col.  Charles  C.  Grant,  after  whom  the  spe- 
cies is  named,  discovered  most  of  the  specimens,  which  are  six  in 
number,  two  in  the  Spencer  collection,  now  destroyed  by  fire,  one 
in  the  Redpath  Museum  of  McGill  University,  Montreal,  another 
in  the  Geological  Survey  of  Canada  at  Ottawa,  and  two  in  the 
Grant  collection,  one  of  which  has  generously  been  donated  to  Yale 
University. 

Remarks. — This  species  is  apparently  closely  related  to  M.  bel- 
lulus,  which  see  for  comparison. 


REVISION   OF   PALEOZOIC    STELLEEOIDEA. 


91 


MESOPAL^EASTER  BELLULUS  (Billings). 

Text  fig.  7. 

Petraster  bellulus  BILLINGS,  Geol.  Surv.  Canada,  Pal.  Foss.,  vol.  1,  1865,  p.  393, 
fig.  368.— MILLER,  N.  Amer.  Geol.  Pal.,  1889,  p.  269,  fig.  389. 

Original  description. — "Deeply  stellate,  about  18  lines  across;  disk 
5  lines  wide;  width  of  rays,  at  the  base,  half  the  width  of  the  disk, 
uniformly  tapering  to  their  extremities;  ambulacral  grooves,  narrow 
and  deep,  with  about  30  adambulacral  plates  on  each  side.  These 
plates  are  strongly  convex  and  nearly  square  [distally,  but  proximally 
are  wider  than  long].  Outside  of  these  there  is  a  row  of  [about  21 
infra]  marginal  plates,  which  appear  to  [actually  do]  extend  to  the 
extremities  of  the  rays,  but  on  this  point  there  is  some  doubt,  as  the 
specimen  is  not  perfect.  [The  four  proximal  pieces  increase  rapidly 
in  size  so  that  they  are  considerably  larger  than  the  others.  All  of 
the  actinal  plates  are  granular.]  There 
appear  to  be  one  or  two  [there  is  but  one 
axillary]  small  disk  plates  between  the 
[basal  adjoining  infra]  marginal  and  ad- 
ambulacral plates  just  outside  of  the  oral 
angles. 

"Locality  and  formation. — Township  of 
Grimsby  [Ontario];  in  the  Niagara  shale 
[  =  Rochester  shale]. 

1  i  Collector. — J  ohnson     Pettlt,    Esq. ,    Fi  G.  ?.— THE  ORIGINAL  FIGURE  OF  ME- 

Grimsby."  The  holotype  is  in  the  Vic- 
toria Memorial  Museum,  Ottawa,  Canada 
(No.  2665). 

Remarks. — The  holotype  and  only 
known  specimen  of  this  species  was  seen 
by  the  writer  at  Ottawa,  and  has  now  been  freed  from  the  rock  so 
that  the  abac  tin  al  side  can  also  be  studied.  The  generic  charac- 
ters are  those  of  Mesopalseaster  and  one  is  impressed  at  once  by  the 
almost  specific  identity  of  the  abactinal  side  of  the  specimen  with 
that  of  M.  granti.  However,  as  the  specimens  show  slight  differ- 
ences and  come  from  different  Siluric  formations,  it  is  thought  best 
to  recognize  them  as  distinct  species.  Moreover,  the  actinal  side 
of  M.  granti  is  still  unknown. 

Abactinally  all  of  the  skeletal  pieces  are  of  about  the  same  size, 
small,  each  ossicle  irregular  in  outline,  and  more  or  less  stellate. 
There  are  about  17  in  the  length  of  one-half  inch.  This  skeleton  is 
more  or  less  disturbed  and  it  is  impossible  to  clean  off  all  the  adhering 
shale,  so  that  it  is  difficult  to  make  out  the  detailed  arrangement. 
The  following,  however,  can  be  made  out:  There  is  no  true  disk  as 
in  Petraster ,  and  the  parts  that  appear  as  such  are  either  adhering 
shale  or  displaced  ossicles  due  to  distortion  during  sedimentation, 


SOPAL.EASTER  BELLULUS,  AFTER  BlL- 
LINGS.  NATURAL  SIZE.  THE  SPECI- 
MEN HAS  STILL  TOO  MUCH  SHALE 
ADHERING  TO  IT  AND  BESIDES  IS  CON- 
SIDERABLY DISTORTED,  PREVENTING 
ITS  BEING  SATISFACTORILY  PHOTO- 
GRAPHED. 


92  BULLETIN    88,   UNITED   STATES   NATIONAL   MUSEUM. 

Distally  the  rays  have  columns  of  small  radial  pieces,  and  outside  of 
these  are  the  two  supramarginal  rows.  Proximally  between  these 
primary  columns  there  appear  accessory  pieces,  one  column  of  which 
wedge  in  between  the  radials  and  supramarginals  and  from  one  to 
three  between  the  latter  and  the  inframarginals.  In  this  way  finally 
as  many  as  13  columns  can  be  counted  at  the  base  of  a  ray. 

The  madreporite  is  situated  near  the  margin  between  adjoining 
supramarginal  columns,  and  is  conspicuously  protruded  and  large 
when  compared  with  the  small  adjacent  ossicles.  It  is  a  large, 
radially  striate,  irregularly  circular  plate  about  six  times  larger  than 
the  adjoining  pieces. 

MESOPALJ2ASTER  CARACTACI  (Gregory). 
Plate  9,  fig.  6;  plate  11,  fig.  1. 

Palseaster  caractaci  SALTER,  Cat.  Foss.  Mus.  Practical  Geology,  1865,  p.  30  (nomen 
nudum). — NICHOLSON  and  ETHERIDGE,  Mon.  Silurian  Foss.  Girvan  Disk, 
Ayrshire,  fasc.  3,  1880,  p.  321  (no  description).— GREGORY,  Geol.  Mag., 
dec.  4,  vol.  6,  1899,  p.  344. — SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk., 
Wiesbaden,  vol.  63,  1910,  p.  227. 

Protopalxaster  caractaci  SPENCER,  Mon.  Brit.  Pal.  Asterozoa,  pt.  1  (Palseontogr. 
Soc.  for  1913),  1914,  pp.  21,  30,  pi.  1,  fig.  5. 

Remarks. — The  writer  was  greatly  pleased  to  receive  from  Dr.  F. 
A.  Bather  of  the  British  Museum  wax  squeezes  of  the  type-specimens^ 
because  they  clearly  show  that  the  genus  Mesopalseaster  is  present  in 
Europe.  M.  caractaci  has  its  closest  relationship  in  M.  sJiafferi,  the 
genotype  of  Mesopald&aster.  The  differences  are  easily  to  be  seen  on 
the  abactinal  side,  as  illustrated  in  this  work. 

Rays  long  and  slender,  abactinally  flattened.  R  =  12.5  mm., 
r—3.S  mm.,  R,  =  3.3r.  Radialia  small  and  no  larger  than  the  pieces 
of  the  accessory  columns  on  either  side  of  them ;  the  former  alternate 
in  position  with  the  pieces  of  the  latter  and  all  of  them  are  more  or 
less  spicular  in  outline.  Basal  radials  slightly  larger  than  the  others. 
The  ossicles  of  the  supramarginal  columns  large  and  solid,  the  most 
prominent  of  the  abactinal  side,  very  large  proximally  and  exceedingly 
small  distally;  there  are  about  14  in  a  column.  Basal  inframarginals 
most  conspicuous  of  all  abactinal  plates,  with  each  pair  occupying 
the  axils,  and  together  with  the  smaller  basal  radialia  form  a  ring 
bounding  the  disk.  The  disk  has  fallen  in  but  still  shows  a  few 
small  pointed  plates. 

"  Madreporite  is  large,  and  placed  close  by  one  of  the  interradial 
angles"  (Gregory). 

Inframarginal  ossicles  almost  smooth,  large  and  prominent  proxi- 
mally, decreasing  rapidly  in  size  so  that  not  more  than  9  can  be 
seen  actinally,  where  the  tiny  pieces  pass  somewhat  over  to  the 
abactinal  surface,  or  better  the  lateral  sides;  Gregory  states  that 
there  are  12  in  a  column.  The  basal  pieces  of  adjacent  columns  do 
not  as  a  rule  touch  one  another  in  the  axils. 


BEVISION   OF   PALEOZOIC   STELLEROIDEA.  93 

Interbrachial  areas  with  single,  large,  hexagonal,  axillary  inter- 
brachial  plates. 

Adambulacral  pieces  quadrangular,  fairly  uniform  in  size  for  two- 
thirds  the  length  of  the  rays  and  then  become  gradually  smaller 
distally;  there  are  about  15  in  a  column.  A  peculiarity ,  of  this 
species  is  that  the  ambulacralia  do  not  continue  around  the  axillary 
interbrachials,  but  cease  with  the  basal  inframarginals.  There  are, 
therefore,  in  M.  caractaci  no  adambulacral  oral  armature  pieces. 

Ambulacral  furrows  moderately  wide,  with  as  many  rectangular 
ambulacralia  as  there  are  adambulacrals,  plus  probably  four  more 
in  each  column,  and  these  continue  around  the  axillary  interbrachial. 
Therefore,  the  oral  armature  consists  entirely  of  ambulacralia.  All 
of  these  ossicles  are  directly  opposite  one  another  and  have  high 
medial  crests  that  are  continuous  across  the  ambulacral  furrow. 
Podial  openings  large  laterally  between  the  plates  and  the  adambu- 
lacrals. 

Locality  and  formation. — Caradoc  sandstone,  Soudley  quarry, 
Church  Stretton,  England.  The  holotype,  a  split  nodule,  is  in  the 
British  Museum  (Natural  History),  No.  48206;  wax  squeezes  from 
which  the  photographs  have  been  made  are  in  the  United  States 
National  Museum.  Other  specimens,  Bather  states,  are  in  the  Museum 
of  Practical  Geology,  London;  these  are  from  Marshbrook  and  occur 
at  a  somewhat  higher  geological  level. 

Remarks. — Gregory  wrote  in  1899  that  "the  nearest  ally  of  this 
species  is  P.  matutina  (Hall),"  but  the  illustrations  here  presented 
wiU  show  that  the  relationship  is  with  Mesopaldeaster  shafferi  and  not 
with  Hudsonaster  matutinus. 

Cat.  No.  60606,  U.S.N.M. 

MESOPAL^EASTER  (?)  ACUMINATUS  (Simonovltsch). 

Asterias  acuminatus  SIMONOVITSCH,  Sitzb.  d.  mat.-naturw.  Classe  Akad.  Wiss., 

Wien,  vol.  64,  Abt.  1,  1871,  p.  100,  pi.  3,  figs.  2-2d. 
Asterias  acwninata  SCHONDORF,  Palaeontographica,  vol.  56,  1909,  pp.  72,  109, 

pi.  11,  figs.  7,  8. — SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden, 

vol.  62,  1909,  p.  32,  pi.  5,  figs.  4,  5. 
Roemeraster  (?)  acuminattis  STURTZ,  N.  Jahrb.  fiir  Min.,  etc.,  1886,  vol.  2,  p.  154. 

Actinally  this  small  and  slender  species  is  nearly  in  harmony  with  the 
generic  characters  of  Paldeaster  and  Hudsonaster,  differing  only  in  that 
the  axillary  interbrachial  plates  barely  extend  to  the  margin  of  the 
disk,  while  in  those  genera  they  are  prominent  and  marginal  in  the 
axils.  In  Asterias  acuminatus  they  are  as  yet  not  crowded  so  far  orally 
as  in  most  species  of  Mesopalseaster.  It  is  a  difference  of  degree,  not 
of  kind;  therefore  this  species  has  more  the  actinal  character  of 
Mesopalseaster  than  Hudsonaster.  Ambulacral  plates  unknown. 

Abactinally  Simonovitsch's  species  is  said  to  have  six  columns  of 
tumid  plates,  all  alike  and  persisting  throughout  the  rays.  If  the 


94  BULLETIN   88,  UNITED  STATES  NATIONAL  MUSEUM. 

outermost  columns  of  each  ray  are  regarded  as  the  inframarginals 
and  the  ones  immediately  inside  as  supramarginals,  two  medial 
columns  remain  to  be  homologized  with  those  in  Mesopalseaster.  If 
Simonovitsch  is  correct,  then  by  this  interpretation  there  are  two 
columns  between  the  supramarginals.  Both  can  not  be  radials  and  to 
regard  one  as  such  will  leave  a  unilateral  and  apparently  an  unnatural 
development.  If  five  or  seven  columns  of  abactinal  plates  were  present, 
this  species  would  be  hi  harmony  with  Mesopalxaster.  Since  Simono- 
vitsch's  work  is  of  the  best,  we  have  at  present  the  only  alternative  of 
supposing  that  the  radials  in  Asterias  acuminatus  are  suppressed  and 
that  its  two  medial  columns  are  homologous  with  the  intercalary 
abactinal  plates  of  other  starfishes.  Among  Paleozoic  asterids  this 
development  is  rare  and  is  found  only  in  Encrinaster  and  Palseaster. 
In  that  event,  A.  acuminatus  is  not  a  Mesopalseaster. 

A  single  example  of  this  species  was  found  in  the  Lower  Devonic 
(probably  Upper  Coblenzian)  near  Braubach,  Germany. 

In  his  revision  of  the  Lower  Devonic  starfishes  of  Germany, 
Schondorf  was  not  able  to  discover  the  whereabouts  of  the  type-speci- 
men and  therefore  had  to  leave  this  species  as  determined  by  Simono- 
vitsch. The  former  states  that  actinally  the  structure  reminds  one 
of  Spaniaster  latiscutatus,  the  genotype  of  Spaniaster,  and  closely 
related  to  Mesopalseaster.  For  further  remarks  see  Spaniaster. 

MESOPAL^ASTER  (?)  CLARKI  (Clarke  and  Swartz). 

Plate  10,  figs.  1,  2. 

Pals&aster  clarki  CLARKE  and  SWARTZ,  Maryland  Geol.  Surv.,  Upper  Devonian, 
1913,  p.  543,  pi.  46,  figs.  3,4. 

Original  description. — "This  species  is  represented  in  the  collec- 
tions by  a  single  specimen  affording  a  pretty  sharp  cast  of  both  sides 
of  a  very  regular  and  complete  individual.  In  general  structure  and 
appearance  the  species  is  quite  similar,  especially  on  the  oral  surface, 
to  Palseaster  eucharis  Hall  of  the  sandy  Hamilton  shales  of  central 
New  York,  but  the  latter  is  a  much  larger  form. 

"The  disk  is  small,  rays  long  and  slender,  thecal  plates  all  promi- 
nently developed.  The  ambulacral  surfaces  are  represented  only  by 
a  narrow  linear  depression  beneath  which  the  ambulacral  plates  are 
concealed.  These  depressions  are  bordered  by  thickened  and  somewhat 
elevated  quadrangular  or  pentangular  ad  ambulacra.  The  marginal 
plates  are  in  single  rows,  much  thickened,  with  generally  quadrangular 
outline  and  convex  surface,  each  projecting  on  the  margin  of  the  ray. 
At  each  axilla  is  a  single  pear-shaped  plate  with  its  apex  outward, 
these  plates  being  the  largest  in  the  individual.  The  abactinal  surface 
is  tessellated  by  rows  of  strong  convex  plates  of  similar  size  to  the  mar- 
ginal plates.  Of  these  there  are  three  rows,  a  median  row  of  narrow 
oval  ones  between  the  ends  of  which  are  interlocked  the  edges  of  the 
much  larger  plates  of  the  lateral  rows  which  are  highly  convex  and 


REVISION   OF  PALEOZOIC   STELLEROIDEA. 


95 


FIG.  8.  —  SPANIASTER  LATISCUTATUS,  AFTER 
SCHONDORF.  SCHEMATIC  ARRANGEMENT  OF 
THE  ABACTINAL  PLATES.  C,  PRESUMABLE 
POSITION  OF  ANUS;  Ce,  CENTRAL  PLATE; 
Jn,  BASAL  INTERRADIALIA;  mdp,  PROBABLE 
POSITION  OF  MADREPORITE;  mo,  SUPRAMAR- 
GINALIA;  RI,  BASAL  RADIALIA. 


thickened  in  the  center  and  greatly  depressed  to  the  sutures .  Thus  each 
plate  has  a  cushioned  surface.  Between  the  ends  of  each  plate  of  the 
middle  row  are  two  minute  accessory  plates  lying  in  the  angles  at 
which  the  lateral  plates  enter.  At  the  base  of  each  ray  and  upon  the 
disk  is  a  single  large  plate  whose  surface  rises  into  a  high  clavate  node. 
Between  each  two  of  these  is  one  of 
less  height..  The  central  portion  of 
the  aboral  area  is  destroyed  and  no 
trace  of  madrepore  is  seen. 

"The  width  of  this  specimen  from 
tip  to  tip  is  33  mm. 

"Occurrence:  Jennings  formation, 
Chemung  member.  Yellow  sandstone 
on  the  road  northeast  of  Oakland, 
Garrett  County  [Maryland],  where  it 
is  associated  with  Spirifer  disjunctus. 

"Collection:  Maryland  Geological 
Survey." 

Remarks. — This  clearly  determined 
species  is  a  late  survival  of  early 
Paleozoic  primitive  asterids.  The 
characters  so  far  as  determinable  in 
the  natural  mold  are  those  of  Meso- 
palseaster,  but  as  the  disk  skeleton  is  not  preserved,  it  is  very  prob- 
able that  when  this  feature  is  known  the  form  will  be  seen  to  belong 
to  a  new  genus. 

Genus   SPANIASTER  Sehondorf. 

Plate  12,  figs.  1,  2;  text  fig.  8. 
Calaster  SANDBERGER  (not  Agassiz  1835),  Verst.  d.  rheinischen  Schicht.  Nassau, 

1855,  p.  381. 

Spaniaster  SCHONDORF,   Jahrb.  nassauisch.  Ver.   Naturk.,  Wiesbaden,  vol.  60, 
1907,  p.  176;  vol.  62,  1909,  p.  30;  Palaeontographica,  vol.  56, 1909,  pp.  73, 109. 

Remarks. — This  genus  with  its  single  very  small  species  has  its 
nearest  relations  with  Mesopalseaster,  in  that  it  has  a  single  axillary 
interbrachial  plate  in  each  actinal  axillary  area,  but  differs  from  it 
in  that  there  are  many  more  adambulacral  and  ambulacral  plates 
than  there  are  inframarginals.  The  marked  and  generic  difference, 
however,  is  on  the  abactinal  side,  where  there  are  but  three  columns 
of  plates,  one  radial  and  two  suuramarginal,  of  large  and  thick  ossicles 
arranged  in  parallel  rows,  the  pieces  of  which  do  not  alternate  with 
one  another;  further,  the  supramarginals  are  almost  completely 
superposed  upon  the  inframarginals,  the  two  columns  together,  but 
more  particularly  the  inframarginals,  bounding  the  rays  and  not  the 
inframarginals  alone,  and  not  so  pronouncedly  as  in  Mesopalseaster. 
The  disk  is  also  more  primitive  in  its  construction,  in  that  the  central 

50601°— Bull.  88—15 7 


96  BULLETIN 

disk  plate  is  encircled  by  a  ring  of  but  5  small  accessory  disk  pieces, 
separating  the  former  from  the  next  ring  of  10  much  larger  plates 
that  are  the  primary  pieces  of  the  radial  and  supramarginal  columns. 
Genoliolotype  and  only  species. — Ccelaster  latiscutatus  Sandberger. 
Restricted  to  the  Lower  Devonic  of  Germany. 

SPANIASTER  LATISCUTATUS  (Sandberger). 
Plate  12,  figs.  1,  2;  text  fig.  8. 

Ccelaster  latiscutatus  SANDBERGER,  Verst.  d.  rheinischen  Schicht.  Nassau,  1855, 

p.  381,  pi.  35,  figs.  1,  la. 
Xenaster  simplex  SIMONOVITSCH,  Sitz.  d.  mat.-naturw.  Classe  Akad.  Wiss.,  Wien, 

vol.  64,  Abt.  I,  1871,  p.  97,  pi.  3,  figs.  1,  la. 
Spaniaster  latiscutatus  SCHONDORF,  Palseontographica,  vol.  56,  1909,  pp.  73-82, 

109,  pi.  8,  fig.  2;  pi.  10,  figs.  2,  9, 10;  pi.  11,  fig.  9  (complete  synonymy  given 

here);  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  62,  1909,  p.  31,  pi. 

5,  figs.  1-3,  text  fig.  2. 

The  Sandberger  specimen,  showing  only  the  abactinal  side,  was 
found  in  the  Lower  Devonic  Spiriferensandstein  at  Unkel,  near 
Bonn,  Germany.  Another  specimen  from  the  Lower  Coblenzian 
quartzite  has  been  recently  found  at  Bienhorntale,  near  Coblenz; 
this  shows  both  sides.  Still  another  is  from  the  Lower  Coblenzian 
at  Oberstadtfeld  in  the  Eifel.  The  holotype  of  X.  simplex  is  from  the 
Upper  Coblenzian  at  Niederlahnstein  on  the  Rhine. 

Genus  MIOMASTER   Sehondorf. 

Plate  8,  fig.  3. 

Miomaster  drevermanni  SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden, 
vol.  62,  1909,  p.  38,  pi.  3,  fig.  4;  pi.  4,  fig.  3. 

Remarks. — This  genus  is  most  closely  related  to  Spaniaster,  in 
that  both  have  the  single  axillary  interbrachial  plates  and  the  infra- 
marginals  and  supramarginals  are  directly  superposed.  They  differ 
from  one  another  mainly  on  the  abactinal  side,  though  this  area  is  so 
poorly  preserved  in  Miomaster  that  almost  nothing  definite  can  be  said. 
Sehondorf  illustrates  a  section  through  .the  rays  that  shows  the 
presence  of  single  columns  of  very  small  accessory  pieces  between 
the  radialia  and  supramarginalia.  In  the  description,  however,  he 
states:  "One  can  not  positively  determine  whether  the  supra- 
marginal  plates  are  separated  from  the  median  pieces  by  small 
accessory  ossicles,  or  whether  the  three  dorsal  columns  were  closely 
adjoining."  The  central  disk  area  is  also  too  much  disturbed  to  make 
out  the  skeletal  arrangement.  There  appear  to  have  been  small 
interbrachial  abactinal  areas.  Under  these  circumstances,  the  genus 
Miomaster  can  not  be  said  to  be  well  established,  and  its  final  dispo- 
sition is  dependent  on  finding  better  preserved  material. 

Genoholotype  and  only  species. — M.  drevermanni  Sehondorf  (as 
cited  above).  A  single  example  was  found  by  Drevermann  in  the 
Upper  Coblenzian  at  Miellen-on-the-Lahn,  Germany.  The  holotype 
is  in  the  Senckenberg  Museum,  Frankfort-on-the-Main. 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  97 

DEVONASTER,  new  genus. 

Plates  11  and  12. 
Palseaster  (part)  of  AUTHORS. 

Xenaster  (?)  or  new  genus  GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6,  1899,  p.  346. 
Devonaster  SCHUCHERT,  Fossilium  Catalogus,  Animalia,  pt.  3,  April,  1914,  p.  14. 

A  characteristic  starfish  of  the  American  Devonic. 

Generic  characters. — Rays  five,  stout,  tapering  rapidly.  Disk 
large,  with  small  interbrachial  arcs. 

Abactinal  area  of  rays  with  prominent  columns  of  radial  supra- 
marginals  and  less  prominent  inframarginal  plates,  all  of  which 
bear  numerous  small  pustules.  The  radial  columns  are  completely 
separated  from  the  supramarginals  by  a  great  abundance  of  very 
small,  conical,  irregularly  arranged,  accessory  plates  which  in  the 
proximal  region  may  also  force  apart  single  plates  of  these  columns. 
The  supramarginal  columns  of  adjoining  rays  nearly  meet  in  the 
axillary  areas  a  short  distance  inside  of  the  margin,  at  which  level 
the  radial  columns  also  cease.  Inside  of  the  area  bounded  by  the 
proximal  plates  of  the  radial  and  supramarginal  columns,  the  disk 
has  numerous  small  accessory  plates  like  those  of  the  rays.  In  the 
center  of  the  disk  is  a  plate  somewhat  more  prominent  than  those 
surrounding  it,  and  just  inside  of  the  adjoining  proximal  supramar- 
ginals is  a  small  but  distinct  plate  interradial  in  position. 

Ambital  accessory  plates  abundantly  developed  between  the 
marginal  ossicles  in  the  axillary  areas.  These  plates  are  like  the 
other  accessory  plates  and  do  not  extend  beyond  the  third  or  fourth 
proximal  inframarginal  pieces,  where  the  ambital  areas  cease  and 
the  supramarginal  ossicles  come  to  lie  more  and  more  completely 
over  the  inframarginals. 

Madreporite  flat  or  concave,  situated  between  two  proximal 
supramarginal  ossicles  and  outside  of  one  of  the  small  interradially 
situated  plates. 

Inframarginal  pieces  lajge  and  thick,  increasing  rapidly  in  width 
proximally,  so  that  the  tw.o  wedge-shaped  proximal  plates  are  nearly 
three  times  as  wide  as  long.  The  plates  are  pustulose,  and  the  proxi- 
mal ones  bear  several  slender  spines. 

Adambulacral  plates  more  numerous  than  the  inframarginals, 
continuing  around  the  axillary  interbrachial  plates,  in  front  of 
which  the  columns  meet  in  two  triangular  and  enlarged  adambu- 
lacral  oral  armature  plates.  Each  piece  bears  two  short,  obtusely 
pointed  spines. 

Ambulacral  grooves  narrow  and  deep,  either  straight  or  very  slightly 
petaloid.  Ambulacral  plates  equaling  in  number  the  adambulacrals 
and  arranged  in  directly  opposed,  closely  adjoining  columns.  Podial 
openings  in  two  columns  through  the  sutures  in  the  lateral  part  of 
the  furrows. 


98  BULLETIN    88,   UNITED  STATES   NATIONAL   MUSEUM. 

Axillary  interbrachial  plates  large,  a  single  one  situated  in  each 
area  between  the  adambulacral  and  inframarginal  columns.  Each 
bears  short,  thick,  blunt  spines. 

Mouth  plates  (tori)  minute,  one  situated  in  front  of  each  pair  of 
oral  armature  plates. 

Genoholotype. — Palseaster  eucharis  Hall. 

Distribution. — Restricted  to  the  Hamilton  and  Chemung  of  the 
American  Devonic.     The  species  are: 
D.  eucharis  (Hall).     Hamilton. 
D.  chemungensis,  new  species.     Chemung. 

Remarks. — This  genus  is  readily  distinguished  from  Hudsonaster 
hi  having  well-developed  radial  and  ambital  accessory  plates,  in 
the  numerous  very  small  plates  of  the  disk  and  in  the  presence  of 
interbrachial  axillary  plates. 

Devonaster  differs  from  Palseaster  in  having  radial  columns  of 
plates  and  in  the  presence  of  three  plates  in  each  interbrachial  area 
against  one  in  Palseaster.  There  are  also  other  differences.  From 
Neopalseaster  it  differs  in  having  ambital  accessory  plates  and  no 
ocular  plates;  while  the  proximal  supramarginals  and  radials  are 
very  large  in  the  former,  they  are  small  in  Devonaster,  particularly 
the  supramarginals,  which  are  not  readily  distinguished  from  the 
accessory  disk  plates.  In  Mesopalseaster  and  Promopalseaster  the 
accessory  plates  are  always  arranged  in  columns  or  rows  and  the 
ambital  accessory  plates  are  not  restricted  to  the  axillary  areas  as 
hi  Devonaster.  Further,  in  those  genera  (excepting  in  the  smaller 
forms  of  Mesopalzeaster)  there  are  always  from  two  to  five  inter- 
brachial marginal  plates,  while  Devonaster  has  but  one  axillary 
marginal  in  each  interbrachial  area. 

Devonaster  greatly  resembles  abactinally  Xenaster  of  the  Lower 
Devonic  of  Germany,  but  is  readily  distinguished  actinally  in  that 
the  latter  has  more  large  interbrachial  plates,  and  especially  in  the  ad- 
dition of  numerous  accessory  interbrachial  pieces.  These  differences 
are  pointed  out  in  more  detail  in  the  remarks  on  Xenaster. 

DEVONASTER  EUCHARIS  (Hall). 

Plate  12,  figs.  3-5. 

Palseaster  eucharis  HALL,  Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  1868,  p. 
287,  pi.  9,  figs.  3-3a  (74);  rev.  ed.,  1868=1870,  p.  330,  pi.  9,  figs.  3-3a  (74).— 
QUENSTEDT,  Petrefactenkunde  Deutschlands,  vol.  4,  1876,  p.  71,  pi.  92, 
fig.  29.— ZITTEL,  Handb.  Pal.,  vol.  1,  1879,  p.  452,  fig.  323.— COLE,  Bull. 
Geol.  Soc.  America,  vol.  3,  1892,  p.  512,  pi.  15.— CLARKE,  Bull.  N.  Y.  State 
Mus.,  No.  158,  1912,  pp.  44-45,  6  pis. 

Xenaster  eucharis  SCHONDORP,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol. 
66,  1913,  pp.  87-96,  pi.  3,  figs.  1,  2,  text  figs.  1-3. 

Original  description. — " Body  rather  large;  the  largest  individual 
being  one  inch  and  seven-eighths  from  the  center  of  the  body  to  the 
extremities  of  the  rays;  the  whole  having  a  robust  aspect;  rays 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  99 

acutely  pointed  at  the  extremity.  Upper  [abactinal]  surface  of 
rays  composed  of  three  [radial  and  two  supramarginal]  ranges  of 
large,  highly  convex  or  tuberculiform  plates  which  are  nearly  cir- 
cular at  the  bases  of  the  rays,  becoming  quadrate  and  widened  to- 
wards the  extremities;  separated  from  each  other  in  the  lower  part 
by  numerous  minute  [accessory]  plates  or  granules,  which  become 
fewer  near  the  middle  of  the  ray,  and  before  reaching  the  extremity. 
The  central  portion  of  the  disk  is  occupied  by  an  elevated  pentagon, 
the  angles  of  which  are  formed  by  the  abrupt  termination  of  the 
central  row  of  plates  of  each  ray:  the  whole  composed  of  very  mi- 
nute, highly  convex  plates,  which  vary  in  size,  the  larger  ones  pen- 
tagonally  arranged.  The  angles  between  the  rays  have  a  few  [nu- 
merous] small  [accessory  ambital]  plates  outside  of  the  outer  ranges 
of  tuberculose  [supramarginal]  plates  on  the  upper  side,  uniting 
with  the  inframarginal  plates  below  [and  not  extending  beyond 
the  third  or  fourth  inframarginal  proximal  plate].  Madreporiform 
tubercle  distinct,  situated  lateraUy  at  the  bases  of  the  outer  [supra- 
marginal]  range  of  large  plates  of  two  adjacent  rays.  Ventral  sur- 
face having  deep  ambulacral  grooves,  bordered  by  two  ranges  of 
strongly  tuberculose  plates;  the  outer  [infra]  marginal  range  con- 
sisting of  27  or  28  plates,  besides  a  large,  round  [or  elliptical],  ter- 
minal or  axillary  [interbrachial]  plate;  the  others  are  wider  than 
long  in  the  basal  portion  of  the  ray,  becoming  gradually  shorter 
towards  the  extremity  where  they  are  rounded.  All  the  [infra] 
marginal  plates  are  visible  from  the  upper  [abactinal]  side,  and 
usually  appear  as  an  additional  range  of  plates  on  each  margin  of 
the  ray,  making  five  with  the  three  properly  belonging  to  the  upper 
surface.  Those  of  the  inner  range  bordering  the  ambulacra  (adam- 
bulacral  plates)  are  smaller  than  the  marginal  plates,  about  38  to 
40  in  number;  the  basal  or  oral  plates  [oral  armature]  are  triangular, 
those  of  the  adjacent  rays  uniting  by  their  longer  margins;  and  with 
a  single  minute  plate  situated  at  these  points.  The  plates  of  the 
exterior  surface,  both  upper  and  lower,  present  a  granulose  or  stri- 
ato-granulose  surface  which  appears  to  have  been  produced  by  short 
setae  or  spines;  and  at  the  angles  of  the  rays  the  marginal  plates 
are  armed  by  a  few  spines,  which  are  as  long  or  longer  than  the 
transverse  diameter  of  the  plates.  Ambulacra  composed  of  a  double 
range  of  short,  broad  poral  plates  (ossicula),  equal  in  number  to 
the  adambulacral  plates ;  their  outer  ends  excavated  on  the  posterior 
border,  forming  a  comparatively  large  pore,  just  within  its  junction 
with  the  adambulacral  plate.  There  appears  to  have  been  [is]  but 
one  range  of  pores  in  each  set  of  ossicula,  but  these  are  large,  dis- 
tinct, and  pass  between  [through  and  not  between]  the  plates." 

The  following  additional  description  is  that  of  Mr.  Cole.     The 
surface  of  the  axillary  interbrachial  plate  "is  granulose  and  bears 


100  BULLETIN   88,  UNITED  STATES   NATIONAL  MUSEUM. 

three  short,  thick,  blunt  pointed  spines.  The  [infra]  marginal  plates 
bordering  each  reentrant  angle  bear  similar  but  more  slender  spines, 
which  are  not  'as  long  as  the  transverse  diameter  of  the  plates.' 
The  spines  are  arranged  in  a  row  near  the  distal  margin  of  the  plates 
and  number  five  on  the  plates  at  the  angle,  the  number  and  size 
decreasing  until  they  disappear  at  the  sixth  or  seventh  plate  from 
the  angle.  All  the  [infra]  marginal  plates  are  nearly  smooth  on  the 
free  margin  and  become  gradually  more  granulose  toward  the  line 
of  junction  with  the  adambulacral  plates.  *  *  * 

"The  adambulacral  plates  are  apparently  less  numerous  than 
stated  in  the  original  description,  and  l  the  single  minute  plate 
[mouth  plates] '  at  the  points  of  the  pairs  of  the  oral  plates  [oral 
armature]  is  visible  in  this  specimen  and  is  armed  with  two  relatively 
long,  slender  spines  which  are  apparently  but  a  part  of  the  full 
armature.  The  adambulacral  plates,  including  the  triangular  oral 
[armature]  plates  bear  well-defined  spines,  which  are  shorter  than 
the  diameter  of  the  plates  to  which  they  are  attached.  Each  plate 
bears  two  spines  so  near  to  the  distal  margin  that  the  impressions 
of  the  short  and  obtusely  pointed  spines  frequently  bridge  the 
well-defined  groove  between  the  adjacent  adambulacral  plates  and 
terminate  near  the  proximal  margin  of  the  next  plate.  The  spines 
decrease  in  size  toward  the  end  of  the  ray  and  a  few  plates  show 
only  one  spine.  The  plates  of  this  range  are  thick,  equaling  two- 
thirds  to  three-fourths  the  depth  of  the  groove.  The  vertical  angle 
of  the  faces  forming  the  lateral  walls  of  the  groove  are  beveled,  so 
that  lateral  extensions  of  the  groove  are  formed  between  each  two 
plates  on  the  same  side.  These  lateral  expansions  are  narrow  and 
shallow  at  the  oral  surface,  deeper  and  wider  inward;  so  that  the 
faces  of  the  adambulacral  plates  near  their  junction  with  the  poral 
[ambulacral]  plates  are  reduced  to  a  narrow  edge  which  projects 
inward  and  nearly  touches  the  corresponding  plate  on  the  other 
side  of  the  groove.  The  general  appearance  of  the  fossil  as  well  as 
the  outline  of  the  rays  at  the  points  where  the  broken  block  presents 
a  transverse  section  of  them  indicates  that  the  plates  have  their 
normal  position,  not  having  suffered  distortion  by  pressure. 

"The  ambulacral  plates  are  shown  by  a  well-defined  mold  of  their 
under  or  external  surface.  The  soft  matrix  which  filled  the  ambula- 
cral furrow  pressed  upon  the  membranes  connecting  the  ambulacral 
plates  and  occupying  their  pores,  and  as  these  membranes  decayed 
it  was  forced  by  gentle  pressure  into  the  pores  and  between  the 
edges  of  the  plates.  The  mold  of  the  groove  is  less  than  one-eighth 
of  an  inch  in  width  in  a  ray  measuring  five-eighths  at  its  base.  The 
upper  surface  of  the  mold  bears  a  narrow  longitudinal  median  ridge 
which  marks  the  junction  of  the  two  ranges  of  ambulacral  plates. 
Similar  transverse  ridges,  which  are  continuous  with  the  lines  mark- 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  101 

ing  the  junction  of  the  inner  faces  of  the  adambulacral  plates,  mark 
the  proximal  and  distal  margins  of  the  ambulacral  plates.  These 
ridges  do  not  cross  at  right  angles  to  the  median  line,  but  include 
between  their  proximal  sides  an  angle  of  about  125°.  These  ridges 
indicate  that  the  ambulacral  and  adambulacral  plates  were  equal 
in  number,  and  that  the  former  were  united  in  pairs  along  a  straight 
median  line  rather  than  in  an  alternate  right  and  left  arrangement 
along  a  zigzag  line,  as  is  shown  in  Dr.  Hall's  figures.  The  pores 
described  as  being  '  excavated  in  the  posterior  border  of  the  ambu- 
lacral plates  and  just  within  their  junction  with  the  adambulacral 
plates'  are  not  clearly  shown  on  this  specimen,  although  there  are 
irregular  and  inconstant  markings  at  some  of  the  points  of  the  molds 
of  the  lateral  extensions  of  the  groove.  A  series  of  pores  near  the 
median  line  is  indicated  by  a  series  of  small  rounded  prominences 
on  each  side  of  the  median  ridge  and  very  close  to  it.  These  promi- 
nences are  opposite  the  lateral  expansions  of  the  groove,  and  one  is 
found  on  the  mold  of  each  ambulacral  plate.  The  pores  appear  to 
have  perforations  very  near  the  edges  of  the  plates,  or  excavations 
in  their  margins." 

Abnormal  development. — Among  the  400  specimens  of  this  species 
recently  found  near  Saugerties,  New  York,  there  are  a  few  indi- 
viduals each  with  but  four  rays,  though  otherwise  they  appear  to 
be  of  normal  development.  This  is  the  first  discovery  of  a  four- 
rayed  starfish  in  the  Paleozoic. 

Formation  and  locality. — In  the  Hamilton  of  the  Middle  Devonic 
near  Hamilton,  Summit  and  Cooperstown,  New  York,  Two  sepa- 
rated rays  of  apparently  this  species  were  found  by  the  writer  in  the 
lower  third  of  the  Hamilton  near  Bartletts  Mills,  south  of  Thedford, 
Ontario.  Two  other  fragments  from  the  same  locality  are  in  the 
University  of  Toronto  (Walker  collection,  No.  1610H).  The  type 
and  other  specimens  are  in  the  American  Museum  of  Natural  History, 
one*  is  in  Colgate  University,  another  at  Wesleyan  University,  and  two 
in  Yale  University  Museum. 

Recently  the  New  York  State  Survey  collected  in  the  Hamilton 
sandstone  at  Mount  Marion,  near  Saugerties,  New  York,  over  400 
examples  of  this  fine  starfish.  They  occur  in  a  limited  area  and 
are  often  found  in  association  with  Grammysia  and  in  such  manner 
that  Doctor  Clarke  believes  the  starfishes  were  feeding  on  the  bivalves. 
This  is  probably  the  most  remarkable  find  of  Paleozoic  starfishes,  and 
is  certainly  so  for  America. 

DEVONASTER  CHEMUNGENSIS,  new  species. 

Plate  11,  fig.  2. 

Of  this  species  only  the  actinal  side  is  known,  and  its  general 
structure  so  far  as  can  be  made  out  is  that  of  D.  eucharis  (Hall). 


102  BULLETIN 

It  differs  from  the  latter  in  that  each  axillary  interbrachial  plate 
bears  one  stout  spine,  while  D.  eucharis  has  three.  Further,  in 
D.  eucharis  six  or  seven  of  the  proximal  inframarginal  plates  of 
each  column  bear  on  their  outer  side  a  number  of  small,  slender 
spines.  In  D.  chemungensis  these  spines  may  also  be  present  but 
in  addition  each  plate  bears  centrally  a  prominent  tubercle  for  the 
articulation  of  a  large  spine. 

Formation  and  locality. — The  type  is  in  the  Museum  of  Columbia 
University,  New  York  City  (No.  6228G).  It  is  from  the  Spirifer 
disjunctus  sandstone  of  the  Chemung  of  " Central  Pennsylvania." 

NEW  GENUS. 

NEW  SPECIES. 

In  the  University  of  Chicago  collection  there  is  a  specimen  (No. 
14397)  collected  by  Professor  Weller  in  the  St.  Louis  limestone  on 
Fountain  Creek,  at  Waterloo,  Illinois.  This  five-rayed  asterid  is 
small,  shows  only  the  abactinal  side,  and  has  very  long  but  narrow 
marginals  and  not  over  six  or  possibly  seven  in  a  column;  the  basal 
plates  of  adjoining  columns  make  the  axils.  Otherwise  the  abactinal 
skeleton  of  the  rays  consists  of  many  small,  loosely  adjoining  pieces 
whose  arrangement  can  not  be  made  out.  Nor  can  the  disk  struc- 
ture be  determined. 

The  relationship  of  this  specimen  seems  to  be  with  the  Promo- 
palseasteridse,  with  possible  nearest  affinity  to  the  genus  Mesopa- 
Ixaster. 

Measurements:  R  =  not  less  than  10  mm.,  r  =  4  mm. 

I'liODVJIOI'-A.ILi^E^STElRIlSr^B,  new  subfamily. 

Progressive  Promopalseasteridse  with  the  interbrachial  areas  com- 
plex and  composed  of  the  single  axillary  interbrachials,  more  than 
one  pair  of  interbrachial  marginals,  and  adambulacral  plates.  Podial 
openings  in  each  ambulacral  furrow  mainly  in  two  columns,  Jbut 
proximally  there  may  be  two  additional  ones  in  a  length  never 
more  than  one-third  the  rays. 

Contains : 

Promopalseaster,  new  genus. 

PROMOPAL^EASTER,  new  genus. 

Plates  13  to  23,  25. 
Palxaster  (part)  of  AUTHORS. 

Promopal&aster   SCHUCHERT,     Fossilium    Catalogus,    Animalia,   pt.  3,    April, 
1914,  p.  24. 

Promos,  chief,  and  aster.  The  largest  and  chief  starfishes  of  the 
American  Ordovic. 

Generic  characters. — Disk  above  medium  size,  with  distinct  and 
angular  interbrachial  arcs.  Rays  five,  slender  to  stout,  more  or  less 
long,  and  tapering.  Some  species  attain  a  large  growth. 


BEVISION  OF  PALEOZOIC   STELLEROIDEA.  103 

Abactinal  area  of  rays  with  numerous  columns  of  small,  more  or 
less  tumid,  closely  adjoining  or  reticulated,  spine-bearing  plates.  A 
medial  radial  and  two  lateral  or  supramarginal  columns  of  plates  are 
usually  more  conspicuous  than  the  accessory  columns;  however,  the 
radial  plates  may  be  also  inconspicuous.  The  longitudinal  arrange- 
ment in  columns  is  usually  most  pronounced,  but  sometimes  the 
plates  on  each  side  of  the  radial  column  may  have  a  decided  diagonal 
arrangement.  Small  accessory  plates  are  usually  inserted  between 
the  columns  of  ossicles  or  between  the  individual  pieces  both  distally 
and  proximally.  Disk  with  numerous  small  accessory  plates  like 
those  of  the  rays,  with  no  apparent  definite  arrangement  except 
the  supramarginal  columns,  which  continue  over  the  disk  and  unite 
angularly  in  the  axillary  areas.  The  larger  plates  bear  several 
short  articulating  spines  of  which  the  one  on  the  apex  is  the  largest. 

Ambital  areas  well  developed,  there  being  one  or  more  columns 
of  small  plates  like  the  radial  accessory  columns  both  in  form  and 
arrangement. 

Madreporite  usually  conspicuous,  radially  striated,  and  situated 
near  the  margin  of  the  disk  between  the  adjoining  columns  of  supra- 
marginal  plates. 

Inframarginal  plates  small  and  numerous  distally  like  the  adambu- 
lacrals,  but  proximally  they  usually  increase  rapidly  in  width  and 
assist  in  forming  the  small  interbrachial  arcs.  Each  ossicle  has 
numerous  small  granules  which  probably  bore  short,  smooth,  articu- 
lating, blunt  spines. 

Adambulacral  plates  distally  like  the  inframarginals,  increasing  in 
width  proximally  and  continuing  around  the  plates  of  the  inter- 
brachial areas.  The  two  proximal  plates  of  adjoining  columns  are 
the  paii^s  of  plates  in  the  oral  armature.  Each  adambulacral  plate 
has  a  more  or  less  well-developed  narrow  ambiilacral  extension  which 
unites  with  the  carina  of  the  ambulacral  plates.  These  extensions 
belong  to  the  adambulacral  plates,  apparently  always  so  distally,  but 
proximally  they  are  often  separated  from  the  adambulacral  plates 
by  sutures ;  throughout  the  greater  portion  of  the  rays  they  are  situ- 
ated medially,  but  in  the  proximal  region  they  are  either  on  the  distal 
or  proximal  edge,  each  alternate  plate  having  the  extension  from 
the  same  corner  a  little  longer.  Each  plate  has  more  or  less  numerous 
spine-bearing  granules  in  addition  to  the  three  larger  articulating 
spines  which  are  inserted  one  on  the  ambulacral  and  two  on  the  lateral 
edge. 

Ambulacral  furrows  generally  very  wide  and  regularly  tapering. 
In  each  ray  there  are  two  columns  of  these  plates  which  are  slightly 
alternating  or  opposite.  The  plates  are  as  numerous  as  those  of  the 
adambulacral  columns,  highly  carinated,  about  as  wide  as  long  in  the 
extreme  distal  portion  of  a  ray,  increasing  rapidly  in  width  proximally 


104  BULLETIN  88,  UNITED  STATES  NATIONAL  MUSEUM. 

and  at  the  base  of  the  rays  may  be  four  times  as  wide  as  long.  The 
podial  openings,  one  to  each  plate  and  in  single  ranges,  are  at  the 
extreme  lateral  edges  excavated  between  the  sutures  of  adjoining 
plates  and  beneath  the  adambulacrals.  Proximally,  however,  every 
other  podial  opening  progresses  inwardly  with  the  joined  carinae  and 
issues  where  these  begin  to  fork.  Here  there  are,  therefore,  four 
columns  of  podial  openings  in  each  ambulacral  furrow.  This  change 
is  indicated  by  the  changed  position  of  the  adambulacral  plate  exten- 
sions and  also  b}7  the  pairs  of  forked  carinse  of  the  ambulacral  plates. 
Throughout  the  greater  portion  of  a  ray  the  carinse  are  regular  and 
alike  on  each  plate,  but  toward  the  mouth  they  change  rapidly  in 
direction  and  soon  they  are  arranged  in  forked  parrs,  one  curving 
distally,  the  other  proximally,  with  the  lateral  portions  of  each  pair 
hi  contact  and  uniting  with  the  extensions  of  the  adambulacral 
plates.  The  most  proximal  plate  of  each  ambulacral  column  is 
usually  considerably  modified,  longer  than  wide,  and  more  or  less 
triangular  in  outline,  between  which  there  is  sometimes  inserted  a 
small  quadrangular  ossicle.  These  pieces  belong  to  the  oral 
armature. 

Interbrachial  areas  of  medium  size,  with  the  interbrachial  marginal 
plates  usually  arranged  in  pairs  but  in  some  forms  the  series  may  be 
terminated  by  single  ossicles.  The  number  of  these  plates  in  an  area 
varies  in  different  species,  there  being  two,  three,  or  five  inside  the 
marginal  inframarginals,  and  all  seem  to  be  derived  from  the 
inframarginal  series  by  inward  crowding. 

Genoholotype. — Palseaster  granulosus  Meek  (not  Hall  =  P.  speciosus 
Meek). 

Distribution.— Restricted  to  the  Middle  and  Upper  Ordovicic  of 
America,  chiefly  within  a  radius  of  50  miles  about  Cincinnati,  Ohio. 
The  following  are  the  known  species: 

P.  wilsoni  (Raymond).     Black  River  (Lowville). 

P.  prenuntius,  new  species.     Trenton. 

P.  sp.  undet.     ?Young  of  P.  speciosus  Meek.     Maysvillian. 

P.  speciosus  (Meek).    Maysvillian. 

P.  granulosus  (Hall).    Lower  Richmond. 

P.  bettulus,  new  species.     Richmond. 

P.  spinulosus  (Miller  and  Dyer).     Richmond. 

P.  exculptus  (Miller).     Richmond. 

P.  wylcqffi  (Miller  and  Gurley).     Richmond. 

P.  dyeri  (Meek).     Maysvillian. 

P.  magnificus  (Miller).     Maysvillian  and  Richmond. 

Remarks. — Eight  of  the  ten  species  here  referred  to  Promopalseaster 

have  been  described  as  Palxaster.     They  have  little  direct  relationship 

with  the  latter  genus  in  that  the  species  are  much  larger,  have  well 

developed  ambital  areas,  numerous  accessory  plates,  well  defined 


REVISION  OF  PALEOZOIC  STELLEEOIDEA.  105 

interbrachial  arcs,  and  from  two  to  five  interbrachial  marginal  plates 
in  each  interbrachial  area.  Promopalseaster  is  a  direct  development 
from  Mesopalseaster,  in  that  it  preserves  the  generic  characters  of  the 
latter,  which  is  in  turn  a  descendant  of  Hudsonaster.  In  Hudsonaster 
there  are  no  interbrachial  plates,  accessory  or  ambit al  columns.  In 
Mesopalseaster  the  single  axillan^  marginal  plate  of  Hudsonaster  has 
been  crowded  orally  and  is  no  longer  a  marginal  but  an  axillary 
interbrachial.  Further,  the  radial  and  both  marginal  columns  are 
more  or  less  completely  separated  from  one  another  by  accessory 
columns  of  smaller  plates.  In  Promopalseaster  this  addition  of 
columns  of  small  plates  is  carried  to  its  greatest  development.  The 
character,  however,  which  is  relied  upon  to  distinguish  it  from  Meso- 
palseaster is  that  Promopalseaster  always  has  two  or  more  interbrachial 
marginal  plates  in  each  interbrachial  area,  while  the  former  genus 
has  one,  the  axillary  interbrachial,  and  Hudsonaster  has  none.  The 
position  and  number  of  axillary  and  interbrachial  marginal  plates 
will  readily  distinguish  these  genera,  but  if  the  abactinal  area  of  a 
new  form  alone  is  seen  it  will  be  difficult  to  determine  whether  it  is  a 
Mesopalseaster  or  Promopalseaster.  Small  size  and  few  accessory 
columns,  especially  ambital,  will  help  somewhat  to  distinguish 
Mesopalseaster  from  Promopalseaster. 

Accepting  Promopalseaster  as  a  descendant  of  Mesopalseaster,  it  is 
seen  that  the  axillary  interbrachial  plates  of  the  latter  have  in  P. 
exculptus  been  followed  by  two  proximal  pieces  of  adjoining  infra- 
marginal  columns.  The  same  is  probably  true  of  P.  spinulosus,  but 
here  no  axillary  interbrachial  has  been  observed.  In  P.  speciosus 
and  P.  bellulus,  another  pair  of  proximal  inframarginals  have  become 
interbrachial  plates,  but  the  axillary  interbrachial  is  also  unknown 
in  this  species.  In  P.  dyeri  and  P.  magnificus  the  axillary  inter- 
brachial is  present  along  with  two  pairs  of  interbrachial  marginals. 
In  other  words,  there  is  in  Promopalseaster  a  constant  increase  in  the 
size  of  the  interbrachial  area  produced  by  the  crowding  of  pairs  of 
proximal  inframarginal  plates. 

P.  speciosus  and  P.  bellulus  are  closely  related  species,  and  so  far 
as  can  be  determined  have  but  two  interbrachial  marginal  plates, 
while  our  theoretic  development  requires  three.  There  is,  however, 
in  each  area  orad  to  the  interbrachial  plates  a  small  hiatus  which  in 
some  cases  appears  to  be  filled  by  extensions  from  the  adambulacral 
plates.  It  seems  therefore  probable  that  the  axillary  interbrachial 
plate  may  be  retained,  but  is  not  now  discernible  on  account  of  its 
small  size  or  adhering  clay;  it  may  also  have  dropped  out  or  have  been 
absorbed  and  its  place  occupied  by  the  adjoining  adambulacral  plates. 

In  a  general  way  it  can  be  stated  that  there  is  also  a  regular  increase 
in  the  number  of  accessory  plates  from  Mesopalseaster  to  Promopalse- 
aster through  P.  spinulosus,  P.  speciosus,  P.  bellulus,  P.  dyeri  into 


106  BULLETIN    88,   UNITED   STATES   NATIONAL   MUSEUM. 

P.  magnijicus.  It  seems  probable  from  the  mature  material  studied 
that  the  most  differentiated  species  of  Promopalseaster,  P.  magnificus, 
passed  through  ontogenetic  stages  comparable  to  Hudsonaster,  Meso- 
palseaster  granti,  and  Promopalxaster  bellulus. 

P.  magnificus  at  present  stands  alone  in  its  beautiful  diagonal 
and  longitudinal  arrangement  of  abactinal  plates. 

PROMOPAL^ASTER  WILSONI  (Raymond). 
Plate  13,  figs.  1,  2. 

Palseasterf  wilsoni  RAYMOND,  Ottawa  Naturalist,  vol.  26,  1912,  p,  77,  pi.  5,  figs. 
1-1. 

Original  description. — "  The  specimen  is  exposed  from  the  abactinal 
side,  and  preserves  the  greater  part  of  one  arm,  the  disk,  and  the 
stumps  of  the  other  four  arms.  The  diameter  of  the  specimen, 
when  complete,  must  have  been  about  75  mm.  (3  inches),  and  the 
diameter  of  the  disk  is  20  mm.  This  is  large  for  a  starfish  from  the 
lower  Ordovician.  The  arms  are  quite  convex,  with  a  gentle  taper, 
reminding  one  somewhat  of  the  common  recent  starfish,  Asterias 
vulgaris,  and  as  in  that  species,  the  arms  were  probably  somewhat 
flexible.  The  greater  part  of  the  abactinal  side  of  the  disk  and  arms 
is  covered  with  small  convex,  overlapping,  V-shaped  plates,  which 
are  arranged  with  the  point  of  the  V  directed  toward  the  margins. 
Along  the  crest  of  each  arm  there  is  a  single  row  of  larger  plates 
(radial  column).  These  plates  are  quite  large  and  hexagonal  in  out- 
line near  the  disk,  but  become  smaller,  triangular,  and  alternate  in 
position  farther  out  on  the  arm.  There  are  two  rows  of  marginals 
[supra  and  infra]  these  plates  being  larger  and  flatter  than  the  other 
plates,  and  covered  with  minute  tubercles,  which  may  be  spine  bases. 
Close  to  the  disk,  the  supramarginals  and  [infra]  marginals  seem  to  be 
of  the  same  size,  both  rectangular,  and  the  plates'  of  the  supra- 
marginal  row  directly  over  those  of  the  marginal  series.  Farther 
out  on  the  arms,  the  plates  are  pentagonal,  those  of  the  two  rows 
alternating  in  position,  and  dove-tailing,  and  the  supramarginals 
are  smaller  than  the  marginals.  One  of  the  marginals,  about  half- 
way out  on  the  arm,  is  1.25  mm.  high  and  of  about  the  same  breadth. 
The  smaller  triangular  plates  which  cover  the  greater  part  of  the 
arm  average  about  0.5  to  0.6  mm.  in  height.  On  one  of  the  arms, 
the  small  triangular  plates  seem  to  be  arranged  in  rows  parallel  to  the 
axis  of  the  arm,  but  the  plates  on  the  longer  arm  seem  to  be  more 
irregular,  although  a  general  arrangement  in  rows  can  be  seen.  On 
this  arm  there  are  a  number  of  very  small  plates  scattered  about, 
especially  on  the  top  of  the  arm,  thus  adding  to  the  irregularity.  The 
triangular  shape  of  these  plates  gives  the  arm  a  neat  pattern,  the  plates 
making  diagonal  rows  backward  and  forward  from  the  row  of  large 
plates  along  the  top  of  the  arm.  The  madreporite,  which  is  nearly 
circular  in  outline,  and  2  mm.  in  diameter,  is  in  position,  but  slightly 


BEVTSION   OF   PALEOZOIC   STELLEROIDEA.  107 

tipped  down  at  the  inner  side,  in  an  interradius,  and  not  far  from  the 
center  of  the  abactinal  side  of  the  disk.  The  surface  is  probably  worn, 
for  it  appears  perfectly  smooth." 

In  places  the  abactinal  ossicles  are  removed,  "disclosing  the  ambu- 
lacral  plates.  These  plates,  which  are  long  and  rather  thick,  seem 
to  be  alternate  in  position.  Two  of  the  plates  seem  to  be  pierced  by 
pores  near  their  proximate  ends,  two  pores  piercing  each  plate  ver- 
tically. Near  the  outer  end  of  the  more  perfect  arm  there  is  a  space 
where  a  few  of  the  small  triangular  plates  are  missing,  and  here  also 
the  ambulacral  plates  can  be  seen  from  the  upper  side.  Each  plate 
has  a  narrow  keel  on  that  side.  Other  details  of  the  plates  of  the 
actinal  side  are  unknown." 

Formation  and  locality. — In  the  Lowville  limestone  at  City  View, 
near  Ottawa,  Canada,  where  this  interesting  asterid  was  found  by 
Miss  A.  E.  Wilson,  in  whose  collection  the  holotype  now  is. 

Remarks. — It  is  interesting  to  note  that  this  fully  developed 
Promopalseaster,  one  closely  related  to  P.  magniiicus  of  the  highest 
Ordovicic,  occurs  in  much  older  rocks;  that  is,  in  the  Black  River 
formation.  This  occurrence  again  brings  out  the  fact  often  noted 
by  the  writer,  that  Paleozoic  asterids  are  slow  to  change  in  characters 
accessible  to  the  paleontologist. 

P.  magniiicus,  like  P.  wilsoni,  Raymond  states,  "has  two  rows 
of  large  marginals  and  a  row  of  large  plates  along  the  top  of  each 
arm,  while  the  greater  part  of  the  surface  is  covered  with  small 
convex  triangular  plates.  Miller  found  the  plates  to  be  spine-bearing, 
a  point  which  can  not  be  definitely  decided  in  the  present  species. 
From  the  photograph  (submitted  by  Schuchert)  it  appears  that  there 
are  spaces  between  the  small  triangular  plates  on  the  abactinal  sur- 
face in  Pals&aster  f  magniiicus,  while  in  P.  ?  wilsoni  these  plates  actually 
overlap  each  other." 

PROMOPAL^EASTER  PRENUNTIUS,  new  species. 
Plate  13,  fig.  3;  plate  15,  fig.  5. 

Remarks. — This  species  is  represented  by  a  good  specimen  showing 
the  actinal  side,  the  other  adhering  to  the  limestone.  R  =  somewhat 
less  than  30  mm.,  r  =  7  mm.  Width  of  ray  at  base  about  9  mm. 

P.  prenuntius  is  closely  related  to  P.  speciosus,  but  is  distinguished 
therefrom  by  the  smaller  size,  less  pustulose  ornamentation  of  the 
plates,  and  the  lower  position  in  the  geological  column.  The  plates 
of  the  axial  area  are  also  more  regular  in  size  and  there  are  in  the 
proximal  region  nearly  always  two  adambulacrals  to  each  inframar- 
ginal;  at  about  mid-length  of  the  rays  the  plates  of  each  of  the  two 
columns  are  about  equal  in  number,  but  every  now  and  then  there 
is  some  duplication  among  the  adambulacrals.  P.  prenuntius  is 
equally  as  spinose  as  P.  speciosus  and  the  former  is  undoubtedly  the 
ancestor  of  the  latter. 


108  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

Formation  and  locality. — The  holotype  was  collected  by  Mr.  Wendt 
near  Frankfort,  Kentucky,  apparently  in  the  Lower  Trenton.  The 
writer's  attention  was  called  to  it  by  Prof.  Arthur  M.  Miller,  who 
has  it  in  his  charge  at  the  State  University  of  Kentucky  at  Lexington. 

PROMOPAL^ASTER,  species  undetermined. 
Plate  14,  figs.  1,  2. 

Asterias  primordialis  ANONYMOUS,  two  lithographic  figures  sent  out  by  the  Western 
Academy  of  Sciences  previous  to  1872  without  description  or  known  author. 

Nothing  more  is  known  of  this  species  than  the  two  good  original 
illustrations  reproduced  here.  These  figures  were  sent  to  F.  B.  Meek 
on  May  18,  1872,  by  Mr.  D.  H.  Shaffer,  of  Cincinnati,  Ohio,  with  the 
following  comment  (they  were  found  in  the  Meek  correspondence 
kept  in  the  United  States  National  Museum):  "The  lithograph  in- 
closed of  this  Asterias  was  found  here,  and  in  the  possession  of 
Joseph  Clark  (deceased).  I  saw  it,  and  this  is  a  faithful  picture  of  it. 
I  think  the  fossil  is  either  in  the  possession  of  his  nephew  or  in  the 
cabinet  of  Maxwell's  Female  Seminary,  which  now  is  the  owner  of 
Mr.  Clark's  cabinet.  I  think  it  is  worthy  a  place  with  Palseaster 
shafferi  in  the  illustrations  of  the  Ohio  Geological  Survey." 

From  the  illustration  one  sees  that  this  form  had  on  the  abactinal 
side  of  the  rays  about  nine  columns  of  ossicles.  Of  these  the  radial, 
supra-  and  inframarginals  are  largest.  Between  the  marginals  there 
is  a  single  column  of  tiny  ambital  pieces,  while  on  each  side  of  the 
radials  are  two  columns  of  small  accessory  pieces.  The  structure  of 
the  disk  pieces  can  not  be  made  out. 

The  interbrachial  areas  are  small  and  do  not  appear  to  have  more 
than  two  inwardly  crowded  inframarginals,  but  there  may  also  be 
present  single  very  small  axillary  pieces. 

The  adambulacral  and  inframarginal  columns  appear  to  have  not 
more  than  20  ossicles  hi  a  column.  Of  ambulacrals  there  are  some- 
what more,  about  25,  and  these  alternate  slightly  with  one  another. 

"Asterias  primordialis"  appears  to  be  the  young  of  Promopalse- 
aster  speciosus  (Meek),  and  the  differences  can  all  be  explained  as  due 
to  incomplete  development;  that  is,  the  former  has  fewer  ossicles  and 
fewer  secondary  columns  of  plates. 

Formation  and  locality. — From  the  hills  of  Cincinnati,  in  the  Mays- 
ville  formation.  The  present  whereabouts  of  this  fine  specimen  is 
unknown.  A  still  smaller  and  younger  specimen  is  in  the  Faber 
collection  of  the  University  of  Chicago  (No.  9567),  and  was  collected 
at  350  feet  above  the  Ohio  River  at  Cincinnati.  It  has  but  a  single 
axillary  plate  in  each  interbrachial  area,  and  about  15  adambulacrals 
in  a  column.  It  is  interesting  to  note  that  in  these  young  individuals 
of  Promopalxaster,  the  smaller  they  are  the  more  they  approach 
Mesopalseaster  and  suggest  Hudsonaster. 


EEVISIOST   OF   PALEOZOIC    STELLEKOIDEA.  109 

PROMOPAL^ASTER  SPECIOSUS  (Meek). 
Plate  14,  figs.  3,  4;  plate  15,  figs.  1-4. 

Asterias  antiquata  LOCKE  (not  A.  antiqua  Troost),  Proc.  Acad.  Nat.  Sci.,  Phila- 
delphia, for  1846-47,  vol.  3,  1848,  p.  32,  fig.  on  p.  33. 

Palseaster  antiquata  HALL,  Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  1868, 
p.  286. 

Palssaster  antiquatus  HALL,  Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  rev.  ed., 
1868=1870,  p.  328. 

Palseaster  granulosus  MEEK  (not  Hall  1868),  Amer.  Journ.  Sci.,  ser.  3,  vol.  4,  1872, 
p.  276;  Geol.  Surv.  Ohio,  Pal.,  vol.  1,  1873,  p.  60,  pi.  4,  figs.  3a-c. 

Palseaster  speciosus  MEEK,  Amer.  Journ.  Sci.,  eer.  3,  vol.  4,  1872,  p.  277  (name  at 
end  of  description);  Geol.  Surv.  Ohio,  Pal.,  vol.  1, 1873,  p.  61  (name  at  end 
of  description). 

Also  see  Promopalxaster,  sp.  undet.,  page  108. 

Original  description  by  Meek  (1873). — " Attaining  a  large  size; 
rays  (as  a  little  depressed  by  accident)  slightly  more  than  twice  as 
long  as  their  breadth  at  their  inner  ends ;  and  tapering  regularly  from 
the  disk  to  their  free  ends,  which  are  rather  acutely  angular;  breadth 
of  the  disk  a  little  less  than  that  of  the  inner  ends  of  the  rays.  Mar- 
ginal pieces  convex  [bearing  numerous  small  spines],  nearly  or  quite 
as  long  as  wide,  numbering  on  each  side,  in  the  whole  length  of  each 
ray  (1.40  inch),  31.  Adambulacral  pieces,  a  size  smaller,  as  long  as 
wide,  convex,  and  numbering  on  each  side  39  to  40;  like  those  of  the 
[infra]  marginal  series,  each  bearing  a  small  spine  [several  spines], 
the  largest  of  which  are  each  about  0.14  inch  in  length  and  0.02  inch 
in  thickness  [between  each  two  adambulacral  plates  just  above  the 
podial  opening  is  inserted  a  large  and  thick  spine],  Ambulacral 
pieces  very  short,  or  nearly  three  times  as  wide  as  long,  apparently 
not  alternating  with  the  adambulacral  pieces,  and  each  provided 
with  a  rather  sharp  ridge  across  nearly  its  entire  breadth.  Dorsal  side 
of  disk  and  rays  composed  of  small  tuberculiform  pieces,  of  which 
about  16  rows  may  be  counted  at  about  half  way  between  the  inner 
and  outer  ends  of  each  ray,  along  the  middle  of  which  those  of  two 
[always  two]  or  three  of  the  rows  are  a  little  larger  than  the  others; 
each  dorsal  piece  bearing  a  minute,  very  short  spine  [they  are  nume- 
rous and  like  those  of  the  marginal  plates].  Surface  of  all  the  pieces 
minutely  granular,  one  of  the  central  granules  always  being  somewhat 
larger  than  the  others  for  the  articulation  of  a  spine  [all  of  these 
granules  bear  spines].  Oral  pieces  and  madreporiform  body  un- 
known." 

Emended  description. — Rays  regularly  tapering.  R  =  44  mm., 
r=  11  mm.,  R  =  4r.  Width  of  ray  at  base  14  mm. 

Abactinal  area  of  rays  covered  by  small,  highly  convex,  tuber- 
culated  plates,  each  bearing  numerous  short  slender  spines.  These 
ossicles  are  arranged  in  longitudinal  columns,  of  which  there  a?e 
15  on  each  ray  at  about  its  mid-length.  The  plates  of  one  or 


110  BULLETIN   88,  UNITED   STATES   NATIONAL  MUSEUM. 

two  median  columns  are  larger  and  more  convex  than  the  three 
columns  immediately  on  each  side,  while  the  pieces  of  the  fourth 
column  are  again  more  pronounced  than  those  on  each  side  of  it,  and 
probably  represent  the  supramarginals.  Between  the  supramarginals 
and  the  inframarginals  are  from  one  to  three  columns  of  ambital 
plates,  and  between  these  are  inserted  here  and  there  some  small 
extra  pieces.  The  extra  pieces  are  mainly  developed  beside  the  supra- 
marginal  columns.  Plates  of  the  disk  like  those  of  the  rays,  but  their 
arrangement  is  unknown. 

Madreporite  unknown. 

Inframarginal  plates  very  convex,  about  as  wide  as  long  except- 
ing near  the  base  of  the  columns  where  they  are  about  twice  as  wide 
as  long.  There  are  about  31  of  these  ossicles  in  a  column,  and  they 
have  numerous  small,  slender,  sharp  spines  articulating  on  well- 
developed  tubercles. 

Adambulacral  plates  greatly  resembling  the  inframarginals. 
They  are  largest  near  the  mid-length  of  each  ray,  diminish  in  size 
distally,  but  proximally  they  hold  their  width  and  decrease  in  length 
and  therefore  are  more  numerous.  There  are  43  plates  in  each 
column  besides  those  in  the  oral  armature.  Ambulacrally  each 
adambulacral  plate  has  a  short  attenuate  extension  which  articulates 
with  the  crests  of  the  ambulacral  plates.  Between  all  the  adam- 
bulacral ossicles  there  is  inserted  in  the  suture  facing  the  ambulacral 
groove  a  single  large,  thick  spine,  excepting  for  a  short  distance 
proximally  where  such  are  inserted  in  every  other  suture.  The 
lateral  surface  of  the  adambulacral  plates  in  the  distal  half  of  the 
columns  bears  numerous  small  spines  like  those  of  the  inframarginal 
series,  but  proximally  these  spines  are  gradually  displaced  by  two 
or  possibly  more  larger  ones  like  those  on  the  ambulacral  face. 

Ambulacral  furrows  wide  and  deep.  Ambulacral  plates  of  adjoin- 
ing columns  opposite,  two  or  three  times  as  wide  as  long,  and  slightly 
overlapping  proximally.  Upon  each  plate  there  is  a  high  median 
ridge  which  arises  at  the  inner  end  of  the  plate  and  abuts  against 
the  short  extension  of  the  adambulacral  plate.  The  podial  open- 
ings are  between  the  plates  and  beneath  the  sutures  of  the  adam- 
bulacral plates,  excepting  near  the  base  of  the  rays,  where  they 
occur  in  every  other  suture.  The  ridges  here  are  sigmoid  and  not 
straight,  as  they  are  more  distally.  There  appear  never  to  be  more 
than  two  rows  of  podia  in  an  ambulacrum. 

In  each  axillary  area  inside  of  two  large  inframarginal  plates  and 
between  the  converging  adambulacral  columns  are  inserted  two 
pairs  of  wedge-shaped  interbrachial  marginal  plates  ornamented 
like  the  inframarginals. 

Formation  and  locality. — The  holotype  and  only  known  specimen 
was  collected  by  Mr.  Charles  B.  Dyer  in  the  Maysvillian  at  Gin- 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  Ill 

cinnati,  Ohio.  It  is  now  in  the  Dyer  collection,  Museum  of  Com- 
parative Zoology  (No.  22),  Harvard  University.  The  original  of 
Astcrias  antiquata  Locke  was  found  at  Cincinnati,  but  the  specimen 
appears  to  be  lost. 

Remarks. — Meek  (1873)  in  describing  this  specimen,  provisionally 
referred  it  to  Palseaster  granulosus  Hall  and  commented  as  follows: 

"Although  this  fine  Star-fish  agrees  pretty  well  in  most  of  its 
characters  with  the  description  of  Palseaster  granulosus  of  Hall  (which 
has  not  yet  been  figured) ,  I  am  far  from  being  entirely  satisfied  that  it 
is  really  the  same,  as  it  seems  to  differ  in  some  important  respects. 
For  instance,  the  rays  of  P.  granulosus  are  described  as  being  'obtusely 
rounded  at  the  extremities';  while  in  the  form  under  consideration 
they  are  rather  acutely  rounded,  if  not  angular.  Again,  instead  of 
having  25  of  the  marginal  pieces  on  each  side,  in  a  space  of  one  inch 
and  a  quarter  from  the  apex  of  each  ray,  and  42  or  43  of  the  adam- 
bulacral,  it  shows  in  this  space  28  marginal  and  only  32  adambula- 
cral  pieces.  The  number  of  the  latter  being  about  10  less  on  each 
side  in  the  same  space — a  rather  decided  difference,  showing  the 
inner  row  to  consist  of  proportionally  larger  pieces.  Its  ambulacral 
ossicula  seem  to  have  the  same  proportional  breadth  and  length  as  in 
the  type  of  P.  granulosus  and  also  have  each  a  similar  ridge  across 
the  middle;  but  these  ridges  do  not  show  the  zigzag  arrangement 
mentioned  in  the  description  of  P.  granulosus.  Prof.  Hall  does  not 
say  how  many  rows  of  pieces  are  seen  on  the  dorsal  sides  of  the  rays 
of  his  species;  but  he  states  that  it  is  probably  the  same  species  that 
the  Western  Academy  of  Sciences  sent  out  lithographs  of  under 
the  name  Asterias  primordialis.  One  of  these  lithographs,  now 
before  me  [reproduced  here  on  plate  14,  figs.  1,  2],  represents  from 
8  to  10  rows  of  these  dorsal  pieces,  which  is  6  or  8  less  than  may  be 
counted  near  the  middle  of  the  rays  of  our  specimen. 

"In  noticing  this  form  in  the  Am.  Jour.  Sci.,  vol.  3  (3d  series), 
p.  277,  I  proposed,  in  case  it  should  be  distinct  from  P.  granulosus, 
to  call  it  P.  speciosus. J) 

With  such  marked  differences  between  P.  granulosus  and  P.  speci- 
osus, and  since  the  type-specimen  of  the  former  can  not  be  located 
to  determine  the  interbrachial  structure,  it  is  deemed  advisable  to 
adopt  Meek's  name  P.  speciosus  for  the  specimen  described  above. 

In  the  upper  portion  of  the  Ordovicic  in  the  Richmond  formation 
occurs  another  closely  related  species,  P.  ~bellulus,  which  is  dis- 
tinguished from  P.  speciosus  in  having  more  slender  rays  and  usually 
a  greater  number  of  plates  in  the  actinal  columns.  The  greatest 
difference,  however,  is  that  it  has  seven  pairs  of  adjoining  adam- 
bulacral  plates  proximal  to  the  interbrachial  plates,  while  in  P. 
speciosus  there  are  but  two  or  three  pairs  of  adambulacrals.  In 
other  words,  the  adambulacral  oral  extensions  are  far  longer  in 
P.  bellulus  than  in  P.  speciosus. 

50601°— Bull.  88—15 8 


112  BULLETIN    88,   UNITED   STATES   NATIONAL   MUSEUM. 

The  illustration  of  Asterias  antiquata  Locke  referred  to  above  by 
Meek  is  very  poor,  and  yet  it  seems  to  be  the  same  species  which 
the  latter  described  as  P.  granulosus  Hall  =  P.  speciosus  Meek. 
This,  however,  can  not  now  be  established  since  the  whereabouts 
of  Locke's  specimen  is  unknown.  Both  specimens  are  from  Cin- 
cinnati and  are  of  about  the  same  size.  Hall  comments  on  this 
species  (1870)  as  follows: 

"This  species  was  noticed  by  Dr.  Locke,  as  cited  above,  but  with- 
out specific  description,  and  expressing  a  doubt  whether  it  was  or 
was  not  identical  with  the  Asterias  antiqua  of  Troost.  The  figure 
would  indicate  a  distinct  species  from  that  of  Dr.  Troost." 

PROMOPAL^EASTER  GRANULOSUS  (Hall). 

« 

Palxaster  granulosa  HALL    Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  1868, 

p.  285. 
Palseaster  granulosus  HALL,  Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  rev.  ed., 

1868=1870,  p.  327. 

Original  description. — "Body  of  medium  size,  five  rayed;  rays  a 
little  more  than  twice  as  long  as  their  breadth  at  base;  obtusely 
rounded  at  the  extremities.  Upper  surface  of  rays  composed  of 
numerous  very  small  tuberculose  or  subspinose  plates;  the  madre- 
poric  tubercle  large,  quite  distinct,  situated  laterally  at  the  base  of 
two  of  the  rays.  Under  surface  of  rays  composed  of  a  [infra]marginal 
range  of  small  tuberculose  plates,  about  25  on  each,  side  in  a  ray 
measuring  one  inch  and  a  quarter  from  base  to  apex;  and  an  inner 
(adambukicral)  range  of  smaller  plates,  of  which  about  42  or  43  can 
be  counted  on  the  same  ray;  the  terminal  or  oral  [armature]  plates 
are  small,  elongate,  subtriangular,  in  pairs  at  the  base  of  the  adjacent 
rays.  Ambulacral  areas  composed  of  a  double  series  of  short,  broad, 
slightly  curved  poral  plates  (ossicula) ,  each  plate  marked  by  a  sharply 
elevated  ridge  along  its  entire  breadth,  commencing  on  the  one  plate 
at  the  outer  posterior  angle  and  terminating  on  the  anterior  inner 
angle,  and  running  in  the  opposite  direction  on  the  adjacent  plate. 
When  the  outer  ridged  surface  of  the  poral  plate  is  ground  away, 
the  narrow  openings  or  pores  are  visible  between  the  plates,  apparently 
in  two  rows  in  each  series,  making  four  ranges  of  pores  in  each  ambu- 
lacral  area.'  (The  marginal  ranges  of  pores  are  obscure,  and  may 
only  be  apparent  [there  is  probably  an  error  here  in  regarding  the 
inner  openings  as  podial  openings].)  On  the  under  surface,  near  the 
bases  of  the  rays,  the  tubercles  bear  short  spines  some  of  which  are 
still  in  place." 

'  *  Some  figures  of  a  Palssaster,  closely  allied  to  or  identical  with  this 
one,  from  Cincinnati,  Ohio,  have  been  circulated  by  the  Natural 
History  Society  of  that  place,  under  the  name  of  Asterias  primordialis; 
but  no  description  of  it  has  ever  been  published,  so  far  as  I  know,  nor 


EEVISION   OF   PALEOZOIC   STELLEKOIDEA. 


113 


do  I  find  it  at  all  recognized  in  the  catalogues."  These  original 
figures  are  here  reproduced  as  Promopalseaster,  sp.  undet.  (pi.  14, 
figs.  1,  2).  The  specimen  is  probably  an  immature  individual  of 
P.  speciosus. 

Formation  and  locality. — The  holotype  was  found  by  Mr.  J.  Kelly 
O'Neall  in  the  Lower  Richmond  formation  near  Lebanon,  Ohio,  and 
was  loaned  to  Hall  for  description.  The  whereabouts  of  the  specimen 
can  not  now  be  located.  Some  years  ago  the  writer  asked  the  late 
Professor  Whitfield  about  it  and  he  answered  that  Halt  had  returned 
it  to  O'Neall,  but  the  latter  in  turn  wrote  (Aug.  27,  1896)  that  he 
had  not  received  it. 

Remarks. — This  species  seems  to  be  distinguished  by  the  smaller 
number  of  plates  in  the  inframarginal  columns,  as  the  following  table 
shows.  However,  until  the  nature  of  the  interbrachial  areas  is  known, 
the  relationship  of  P.  granulosus  to  other  Paleozoic  forms  can  not 
be  stated. 


Inframar- 
ginals. 

Adambu- 
lacrals. 

Inter- 
brachials. 

Adambu- 
lacrals 
orad  to 
inter- 
brachials. 

P  granulosus  (Hall)                                      

25 

42-43 

P  speciosus  (Meek)  .       *                 

31 

43 

4 

4 

P  bellulus  new  species  .            

31-38 

48-55 

4 

8 

P.  magnificus  (Miller)  .            

45 

50-52 

5 

5-6 

PROMOPAL^ASTER  BELLULUS,  new  species. 
Plate  15,  figs.  6-8;  plate  16,  fig.  1;  plate  18,  figs.  4,  5. 

R  =  36  mm.,  r=  10  mm.,  R  =  3.6r.      Width  of  ray  at  base,  11.5  mm. 

A  first  view  of  this  species  gives  the  impression  of  P.  speciosus 
(Meek).  Of  the  latter  but  a  single  specimen  is  known  and  it  is  now 
lost,  while  of  P.  bellulus  there  are  numerous  examples,  all  of  which 
have  the  same  specific  characters.  The  specimens  preserved  in  lime- 
stone have  the  rays  more  slender,  while  those  from  soft  shale  are  as 
stout  as  in  P.  speciosus. 

In  the  holotype  of  P.  bellulus  from  limestone  there  are  55  adam- 
bulacral  and  38  inframarginal  plates  in  each  column,  while  in 
P.  speciosus  there  are  43  and  31  plates,  respectively,  in  the  same 
columns.  Shale  specimens  of  P.  lellulus  have  less  plates  in  a  column. 
One  of  these,  a  somewhat  smaller  specimen  than  the  holotype,  has 
31  inframarginal  plates,  the  same  number  as  in  P.  speciosus,  and 
about  48  adambulacrals  in  each  column.  P.  bellulus  has  therefore 
from  31  to  38  inframarginal  plates  and  from  48  to  55  adambulacral 
plates  in  each  column. 


114  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

A  more  important  distinguishing  character  exists  in  the  inter- 
brachial  areas.  In  P.  lellulus  and  P.  speciosus  there  are  two  pairs 
or  four  inter brachial  marginal  plates,  while  the  number  of  adjoining 
adambulacral  plates  is  greater.  In  the  latter  there  are  four  of  these 
on  each  side,  while  in  the  former  there  are  eight.  In  other  words, 
the  interbrachial  areas  in  P.  lellulus  are  much  more  elongated  orally 
than  in  P.  speciosus  and  the  interbrachial  arcs  are  also  greater. 

Abactinally  on  the  rays  the  arrangement  and  number  of  columns 
of  plates  appear  to  be  very  much  like  those  in  P.  speciosus.  The 
individual  plates  are,  however,  less  convex,  cruciform,  more  like  those 
of  P.  spinulosuSj  and  have  stronger  and  more  abundant  spines.  The 
spines  in  P.  bellulus  are  very  numerous,  short,  and  slender,  and  are 
inserted  one  on  the  apex  of  each  plate  and  a  number  around  the  sides 
in  the  angles  between  the  radial  extensions.  In  P.  speciosus  the  spines 
are  grouped  over  the  convex  area  of  the  plate  and  around  the  larger 
central  spine.  The  arrangement  of  the  plates  of  the  disk  appears  to 
have  no  marked  pattern  and  consists  of  very  numerous  small  plates 
like  those  of  the  rays. 

The  adambulacral  plates  each  bear  three  spines  as  in  P.  speciosus 
and  increase  in  size  toward  the  base  of  the  rays.  One  is  inserted  on 
the  inner  or  ambulacral  face  of  the  plate  and  the  two  closely  adjoining 
ones  immediately  above  and  laterally  on  the  rounded  surface. 

Ambulacral  plates  as  in  P.  speciosus. 

Madreporite  of  medium  size,  subcircular  in  outline,  with  numerous 
straight,  sharp,  radiating  ridges.  It  is  inserted  proximally  between 
two  adjoining  columns  of  supramarginal  plates. 

A  development  occurring  only  in  this  species  of  Promopalseaster 
is  a  single  plate  oral  to  the  proximal  adambulacrals.  This  plate 
has  been  seen  in  four  axillary  areas.  It  may  be  a  modified  ambu- 
lacral and  may  correspond  to  a  similar  plate,  which  is  an  ambulacral, 
hi  P.  exculptus. 

Formation  and  locality. — Of  this  species  quite  a  number  of  speci- 
mens were  secured  by  Mr.  Harris  in  the  Waynesville  beds  of  the 
Richmondian.  They  are  all  in  the  United  States  National  Museum. 
One  excellent  specimen  (the  holotype)  showing  the  actinal  area, 
and  two  smaller  poorer  specimens  are  attached  to  limestone,  while 
eleven  fair  specimens  and  fragments  of  eight  other  individuals  are 
from  a  soft  blue  shale  associated  with  Zygospira  modesta  and  Ptilo- 
dictya  sliafferi  (upper  form).  All  were  secured  in  the  vicinity  of 
Waynesville,  Ohio.  The  shale  specimens  were  exhumed  from  one 
small  area,  showing  that  probably  many  starfishes  could  be  similarly 
secured  by  collectors,  since  these  soft  specimens  in  weathering  out 
are  broken  up  and  lost;  more  asterids  will  be  found  when  they  are 
dug  or  quarried  for.  Another  good  specimen  is  in  the  Gurley  col- 
lection of  the  University  of  Chicago  (No.  10983)  and  was  found  at 
Versailles,  Indiana. 


REVISION   OF  PALEOZOIC   STELLEEOIDEA.  115 

Remarks. — The  similarity  and  difference  between  P.  bellulus  and  P. 
speciosus  are  pointed  out  above.  Another  related  species  is  P.  spinu- 
losus,  which  has  the  same  kind  of  abactinal  plates  and  madreporite 
as  P.  bellulus.  In  the  former  the  rays  are  far  longer  and  narrower, 
with  fewer  ambital  plates  and  columns  between  the  supramarginals. 
Actinally  P.  spinulosus  is  at  once  distinguished  from  P.  bellulus 
in  the  much  smaller  interbrachial  areas,  in  that  it  does  not  have 
more  than  two  interbrachial  marginal  plates  while  P.  bellulus  has 
four.  In  the  latter  species  there  are  also  far  more  adambulacral 
plates  around  the  interbrachial  pieces. 

It  will  always  be  difficult  to  distinguish  fragments  of  P.  bellulus, 
P.  speciosus,  and  P.  spinulosus  from  one  another,  even  with  good 
material,  since  at  least  two  specimens  of  P.  bellulus  were  identified 
as  Palseaster  granulosus  Hall  =  Promopalseaster  speciosus  (Meek) . 

Cat.  No.  40879,  U.SJST.M. 

PROMOPAL^EASTER  SPINULOSUS  (Miller  and  Dyer). 
Plate  16,  fig.  2;  plate  17,  figs.  1,  2;  plate  18,  figs.  1-3. 

Compare  with  Promopalseaster  exculptus  (Miller). 

Palseaster  spinulosus  MILLER  and  DYER,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol. 

1,  1878,  p.  32,  pi.  2,  figs.  12-126. 
Palxaster  longibrachiatus  MILDER,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  1,  1878, 

p.  102,  pi.  3,  fig.  4. 

Original  description  (of  Palseaster  spinulosus). — "Pentagonal; 
rays  longer  than  the  diameter  of  the  body;  marginal  plates  globular 
near  the  apices  of  the  rays,  but  lengthened  toward  the  junction 
with  the  body.  Six  of  these  plates  measure  from  the  body  on  a  ray 
three- tenths  of  an  inch.  Two  wedge-shaped  plates  form  the  junc- 
tion of  the  marginal  plates  with  the  body. 

"  Adambulacral  plates  a  little  smaller  [in  width]  than  the  margi- 
nal pieces,  and  possessed  of  two  or  three  [four  or  more]  spines  to 
each  plate.  These  spines  taper  to  a  fine  point,  and  are  longer  than 
the  diameter  of  the  plates.  The  oral  pieces  are  not  determined 
[they  are  like  those  in  P.  exculptus].  The  ambulacral  plates  have 
their  greatest  length  across  the  rays,  and  are  possessed  of  a  sharp 
ridge  in  the  middle  which  seems  to  be  [is]  connected  at  one  end  with 
the  adambulacral  pieces.  [The  entire  number  of  plates  in  each 
range  can  not  be  given,  since  the  rays  are  imperfect.]- 

"The  dorsal  side  is  covered  with  plates  united  by  angular  exten- 
sions. They  are  of  unequal  size,  and  strongly  tuberculated  or  spi- 
nous. 

"The  madreporiform  tubercle  on  its  upper  face  is  an  oblate  sphe- 
roid, much  depressed,  and  marked  by  fine  radiating  stride,  which 
become  more  numerous  by  intercalation,  without  bifurcation. 
[This  plate  is  interpolated  between  the  proximal  plates  of  two  ad- 


116  BULLETIN   88,  UNITED   STATES  NATIONAL  MUSEUM. 

joining  columns  of  supramarginal  ossicles  and  about  medially  be- 
tween the  margin  and  the  center  of  the  disk.]" 

Supplementary  description. — II  unknown,  r=7  mm.  Width  of 
ray  at  base  9  mm. 

Abactinal  area  of  rays  margined  by  inframarginals,  above  and 
inside  of  which  are  columns  of  large,  bipyriform,  multispinous,  su- 
pramarginal plates  of  which  there  are  five  in  5  mm.  at  the  base  of  a 
ray.  The  columns  of  adjoining  rays  unite  in  the  axillary  areas. 
Inside  of  the  supramarginal  columns  the  rays  and  disk  have  numer- 
ous smaller  accessory  plates,  usually  triangular  in  outline  or  vari- 
ously stellate.  They  lie  upon  or  against  each  other,  each  ossicle 
bearing  at  least  one  small  spine,  and  leave  between  them  numerous 
abactinal  openings.  Outside  of  the  supramarginal  plates  in  the 
ambital  areas  are  spicular  ambit al  plates  which  cover  the  abactinal 
side  of  the  inframarginals. 

Description  of  the  type  of  Palseaster  longibrachiatus. — 11  =  38  mm., 
r  =  7  mm.,  R  =  5.4r.  Width  of  ray  at  base  9  mm. 

Rays  large,  slender,  tapering  slowly;  actinally  somewhat  convex 
at  their  outer  ends,  but  elsewhere  concave. 

Abactinal  area  unknown. 

Inframarginal  plates  granular,  large,  decreasing  gradually  in  size 
dis tally,  highly  convex,  in  outline  tetragonal  or  pentagonal  and 
common  to  both  the  abactinal  and  actinal  areas.  From  28  to  30 
plates  in  a  column  on  each  side  of  a  ray. 

Axillary  areas  occupied  by  the  proximal  plates  of  adjoining  infra- 
marginal  columns,  and  in  the  interbrachial  areas  there  are  two  sub- 
quadrangular  or  sub  triangular  interbrachial  marginal  plates.  There 
may  be  an  additional  small  single  plate  in  each  area. 

Adambulacral  plates  greatly  resembling  the  inframarginal  ossicles. 
Distally  they  progressively  overlap  the  inframarginal  plates  con- 
siderably, while  proximally  they  gradually  increase  in  size  and  are 
entirely  inside  and  depressed  beneath  the  plane  of  the  marginal 
columns.  Orally  the  columns  of  adjoining  rays  unite  in  two  wedge- 
shaped  modified  adambulacrals  (oral  armature  pieces) . 

Ambulacral  furrows  deep  and  gradually  tapering.  Ambulacral 
plates  unknown. 

Formation  and  locality. — The  type  of  Palseaster  spinulosus  (No.  16, 
Mus.  Comp.  Zool.)  is  said  to  have  been  found  at  Cincinnati,  Ohio. 
This  is  probably  an  error,  since  il/s  color  and  preservation  indicate 
the  Richmond  formation  and  that  it  comes  from  some  locality 
considerably  to  the  north  of  Cincinnati.  The  only  other  known 
specimen,  the  type  of  P.  longibrachiatus,  was  found  in  the  Richmond 
formation  near  Clarksville,  Ohio,  and  is  in  the  Harris  collection, 
United  States  National  Museum. 

Remarks. — The  type-specimen  of  Palseaster  spinulosus,  which  is 
free,  preserves  but  the  disk  and  a  small  proximal  portion  of  the  rays. 


REVISION   OF   PALEOZOIC    STELLEROIDEA.  117 

Comparing  it  with  the  actinal  area  of  P.  longibrachiatus  Miller,  it 
is  evident  that  both  forms  are  identical.  In  the  latter  the  rays  are 
complete,  very  long  and  slender,  and  there  is  nothing  to  show  that 
they  were  dissimilar  in  P.  spinulosus  Miller  and  Dyer.  Both  types 
are  nearly  of  the  same  size  and  the  actinal  plates  are  identical  in  form 
and  arrangement.  The  abactinal  area  in  P.  longibrachiatus  is  not 
known,  but  since  its  actinal  structure  is  that  of  Promopalseaster 
spinulosus  it  is  safe  to  assume  that  the  abactinal  structure  is  alike 
in  both. 

P.  spinulosus  actinally  is  also  closely  related  to  P.  exculptus  (Miller). 
The  latter  appears  to  have  shorter  and  more  rapidly  tapering  rays 
and  in  general  seems  to  be  a  more  robust  species.  Another  character 
by  which  these  species  can  be  separated  is  that  the  interbrachial 
areas  in  P.  spinulosus  have  two,  while  P.  exculptus  has  three  inter- 
brachial marginal  plates.  It  is  possible  that  the  former  species 
also  has  three  interbrachial  marginal  plates,  but  as  yet  the  small 
single  piece  of  each  area  has  not  been  observed,  while  in  P.  exculplus 
it  is  distinctly  present  in  each  of  the  five  areas.  Should  P.  spin- 
ulosus also  prove  to  have  three  interbrachial  plates,  it  would  be  diffi- 
cult to  distinguish  it  actinally  from  P.  exculptus. 

P.  dyeri  and  P.  magnificus  are  far  larger  species  and  have  five 
interbrachial  marginal  plates  in  each  area. 

Cat.  No.  40881,  U.S.N.M. 

PROMOPAL-EASTER  EXCULPTUS  (Miller). 

Plate  18,  fig.  7;  plate  20,  fig.  2. 

Compare  with  Promopalasaster  spinulosus  (Miller  and  Dyer). 
Palseaster  exculptus  MILLER,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.4, 1881,  p.  69, 
pi.  1,  fig.  1. 

Original  description. — " Pentagonal;  rays  a  little  longer  than  the 
diameter  of  the  body;  diameter  of  the  body,  about  0.93  inch;  length 
of  ray  measuring  to  the  center  of  the  body  or  disk,  about  1J  inches; 
breadth  of  a  ray  at  the  junction  with  the  body,  about  0.57  inch;  rays 
obtusely  pointed. 

"The  [infra-]  marginal  range  consists  of  somewhat  quadrangular 
plates,  having  a  width  a  little  greater  than  the  length;  the  first  8 
of  these  have  a  length  of  one-half  inch,  and  there  are  about  18  in 
the  length  of  an  inch,  and  not  far  from  25  in  each  range,  though  the 
specimen  does  not  permit  us  to  make  the  count  with  certainty.  The 
surface  is  strongly  tubercular,  and  was  probably  spinous  [originally 
covered  with  numerous  small  spines]. 

"The  adambulacral  range  consists  of  about  28  [25]  plates,  on  each 
side  of  a  ray;  they  are  narrower  than  the  marginal  plates,  but  have 
about  the  same  length.  Each  plate  [has  a  short  ambulacral  exten- 
sion conforming  with  the  ridge  of  the  ambulacral  plates  and]  bore 


118  BULLETIN   88,  UNITED  STATES   NATIONAL  MUSEUM. 

strong  spines,  and  some  of  them,  preserved  on  our  specimen,  have 
a  length  greater  than  the  length  of  a  plate.  *  *  * 

"The  ambulacral  plates  have  their  greatest  length  across  the  rays, 
thus  providing  a  wide  ambulacral  furrow.  Each  plate  is  furnished 
with  a  sharp  ridge  in  the  middle,  that  curves  slightly  outward,  from 
the  center  toward  the  adambulacral  range,  increasing  in  height 
until  it  approaches  or  abuts  against  the  adambulacral  plate.  *  *  * 
The  appearance  of  having  been  carved  out,  which  is  presented  by 
the  ambulacral  plates,  suggested  the  specific  name.  [The  plates  of 
adjoining  columns  are  opposite  one  another  or  slightly  alternate.] 

"The  dorsal  side  and  madreporiform  tubercle  unknown." 

Supplementary  description. — R  =  37  mm.,  *r=12  mm.,  R  =  3.1ri. 
The  specimen  is  very  much  flattened  and  the  exact  width  of  a  ray 
can  not  be  given  but  appears  to  have  been  about  10  mm.  at  the  base. 

In  the  axils  of  the  rays  the  proximal  inframarginal  plates  of  adjoin- 
ing rays  rest  against  each  other,  inside  of  which  are  two  wedge-shaped 
interbrachial  marginal  plates.  Orad  to  these  and  adjoining  the  pairs 
of  proximal  adambulacrals  (oral  armature  pieces)  is  situated  a  single 
subquadrate  ossicle,  making  three  interbrachial  marginal  plates  in 
each  interbrachial  area. 

The  podial  openings  in  the  ambulacral  grooves  are  between  the 
sutures  of  adjoining  adambulacral  and  ambulacral  plates  along  the 
line  where  these  two  columns  adjoin.  The  proximal  ambulacral 
plates  orad  to  the  axial  adambulacrals  are  considerably  modified 
and  are  to  be  considered  as  parts  of  the  oral  armature.  A  single 
rather  large  plate  is  here  partially  wedged  between  the  pair  of  termi- 
nating adambulacrals,  and  on  each  end  of  it  abuts  a  single  broadly 
triangular  plate,  a  modified  ambulacral,  completing  the  oral  ends  of 
the  ambulacral  columns  (see  drawing,  pi.  20,  fig.  2). 

Formation  and  locality. — In  the  Richmond  formation  near  Waynes- 
ville,  Ohio.  The  holotype  and  only  specimen  is  in  the  Harris  collec- 
tion of  the  United  States  National  Museum. 

Remarks. — This  species  is  near  P.  spinulosus,  but  apparently  had 
wider,  shorter,  and  more  rapidly  tapering  rays.  There  appear  to  be 
but  two  interbrachial  marginal  plates  in  P.  s-pinulosus,  while  P. 
exculptus  has  three  in  each  area.  Should  the  former  species  also  prove 
to  have  three  plates,  a  possibility,  P.  exculptus  will  be  actinally 
identical  with  P.  spinulosus.  The  wider  and  more  rapidly  tapering 
rays  of  P.  exculptus  can  then  be  explained  by  the  fact  that  the  type- 
specimen  is  considerably  distorted,  since  the  adambulacrals  and  infra- 
marginals  now  lie  wholly  outside  of  the  ambulacrals,  which  are  com- 
pletely exposed,  an  unnatural  condition.  So  long  as  the  abacti- 
nal  area  of  P.  exculptus  remains  unknown  the  species  had  best  be 
retained. 

Cat.  No.  60608,  U.S.N.M. 


REVISION   OF   PALEOZOIC    STELLEROIDEA.  119 

PROMOPAL^ASTER  WYKOFFI  (Miller  and  Gurley). 
Plate  18,  fig.  6;  plate  19,  fig.  2. 

Palxaster  wykoffi  MILLER  and  GURLEY,  Bull.  No.  12,  Illinois  State  Mus.  Nat. 
Hist.,  1897,  p.  46,  pi.  3,  fig.  27. 

Original  description. — " Species  medium  size  [R  =  26  mm.,  r  =  8  mm. 
Width  of  ray  at  base  10  mm.]  Rays  pateliform;  length  about  one 
and  a  half  tunes  the  diameter  of  the  body;  breadth  of  a  ray  at  the 
place  of  junction  with  the  body,  about  two-thirds  the  diameter  of 
the  body;  obtusely  pointed. 

"Marginal  [inframarginal]  plates  wider  than  long  and  numbering 
about  15  in  the  length  of  half  an  inch  from  the  body  [or  about  28 
in  a  complete  column].  The  [infra]  marginal  plates  curve  regularly 
around  the  tips  of  the  rays.  The  adambulacral  range  curves  around 
the  ends  of  the  rays  within  the  marginal  plates  and  consists  of  sub- 
quadrate  plates,  wider  than  long.  They  are  a  little  shorter  than  the 
marginal  plates,  so  that  there  are  about  18  in  the  length  of  half  an 
inch  [about  35  in  a  complete  column].  There  are  10  oral  plates  [oral 
armature]  at  the  junction  of  the  adambulacral  rows,  which  present 
triangular  extensions  toward  the  center  of  the  ventral  cavity.  A 
single  irregular  axillary  plate  rests  between  the  terminal  marginal 
plates  and  the  angle  formed  at  the  junction  of  the  adambulacral 
plates  [this  description  is  inadequate,  see  beyond  for  the  detail]. 
The  ambulacral  plates  have  their  greatest  length  across  the  rays, 
thus  providing  a  wide  ambulacral  furrow.  Each  plate  is  furnished 
with  a  sharp  ridge  in  the  middle,  extending  from  the  middle  furrow 
to  the  adambulacral  plates. 

"Our  specimen  exposes  only  the  ventral  side  and  no  spines  are 
preserved.  It  is  a  well-marked  and  beautiful  species." 

Formation  and  locality. — Found  in  the  Richmond  formation  "near 
Madison,  Indiana,  by  Charles  W.  Wykoff,  in  whose  honor  we  have 
proposed  the  specific  name."  The  holotype  is  now  in  the  Gurley 
coUection  of  the  University  of  Chicago  (No.  6066). 

Remarks. — Each  interbrachial  area  begins  orally  with  a  pair  of 
elongate  triangular  basal  adambulacrals  (the  oral  armature  pieces) 
dis tally  to  which  there  are  two  pairs  of  adjoining  adambulacrals 
followed  by  a  single  axillary  ossicle  and  usually  one  but  also  more 
or  less  of  a  second  pair  of  interbrachial  marginal  plates.  P.  wylcoffi 
is  therefore  distinguished  from  P.  exculptus  in  that  it  has  orally  to 
the  single  interbrachial  plate  two  pairs  of  proximal  adambulacrals 
instead  of  one  as  in  the  last-named  species.  These  differences  are 
not  decided,  and  it  may  eventually  be  seen  when  more  well-preserved 
material  is  at  hand  that  they  are  either  individual  variations  or  due 
to  differences  in  age. 


120  BULLETIN"  88,  UNITED  STATES  NATIONAL  MUSEUM. 

P.  wykoffi  also  greatly  resembles  Anorfhaster  miamiensis,  but  the 
interbrachial  areas  in  the  latter  are  entirely  composed  of  adambu- 
lacral  plates,  there  being  no  interbrachial  marginals  present.  While 
both  species  attained  a  similar  size,  another -difference  is  that  the 
former  has  a  greater  number  of  plates  in  the  adambulacral  and 
inframarginal  columns. 

PROMOPAL^EASTER  DYERI  (Meek). 

Plate  18,  fig.  8;  plate  20,  figs.  3-6;  plate  25,  fig.  1. 

Palseaster  dyeri  MEEK,  Amer.  Journ.  Sci.,  ser.  3,  vol.  3,  1872,  p.  257;  Geol.  Surv. 
Ohio,  Pal.,  vol.  1,  1873,  p.  58,  pi.  4,  figs.  2a-2/. 

Original  description  (1873). — "Among  the  specimens  loaned  to  me 
for  study  and  description  by  Mr.  Dyer,  there  is  a  very  imperfect 
example  of  one  of  the  largest  known  species  of  Silurian  Starfishes. 
When  entire,  it  could  scarcely  have  measured  less  than  5  inches  in 
diameter  [R  =  probably  3  inches,  or  75  mm.]  across  from  end  to  end 
of  the  rays  on  opposite  sides;  and  it  presents  a  breadth  of  disk  (as 
flattened  by  pressure)  of  about  2  inches  [r  =  probably  seven-eighths 
inch,  or  22  mm.].  Its  state  of  preservation  is,  unfortunately,  such  as 
not  to  admit  of  systematic  description,  but  I  think  enough  of  its 
character  can  be  given  to  enable  the  student  to  identify  it,  by  the 
additional  aid  of  figures. 

"The  dorsal  side  of  both  disk  and  rays  is  composed  of  numerous 
small  pieces  [with  stellate  extensions],  with  the  pores  between  them 
apparently  so  large  that  these  pieces  only  seem  to  touch  at  three  to 
four  salient  points  of  each,  so  as  to  form  a  kind  of  reticulated  struc- 
ture; while  they  each  bear  a  little  central  tubercle,  with  a  minute  pit  in 
its  top  for  the  articulation  of  small,  short  [blunt]  spines,  generally 
about  0.07  to  0.09  inch  in  length,  and  about  0.02  to  0.03  inch  in 
thickness.  [Each  plate  bears  but  one  of  these  spines  and  there  appear 
to  be  no  other  smaller  spines.] 

"In  one  of  the  axilla  between  two  of  the  rays  the  so-called  madri- 
poriform  body  can  be  seen  near  the  margin  of  the  disk.  It  is  nearly 
flat,  of  an  obtusely  subtrilobate  form  [probably  cruciform],  with  a 
breadth  or  transverse  diameter  of  0.30  inch,  and  a  diameter  at  right 
angles  to  the  same  of  0.24  inch  [not  less  than  10  mm.].  Its  lobed 
edge  is  directed  inward  toward  the  middle  of  the  disk,  and  its  middle 
lobe  is  largest,  and  shows  the  little  divisions  between  the  slits  or 
furrows,  diverging  and  bifurcating  inward  like  the  nervation  in  the 
pinnules  of  some  kind  of  ferns;  while  in  the  smaller  lateral  lobes  these 
markings  diverge  outward. 

"The  ventral  side  is  also  much  obscured  by  the  adhering  matrix, 
and  numerous  detached  and  confusedly  mingled  spines.  A  row  of 
comparatively  small,  tumid,  nearly  square  [infra]  marginal  pieces, 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  121 

however,  can  be  seen  in  places,  on  each  side  of  the  ambulacral 
furrows,  and  alternating  with  a  row  of  similar  but  slightly  smaller 
adambulacral  pieces,  the  number  of  pieces  in  each  side  of  these  being 
about  the  same.  [In  the  proximal  portion  of  a  ray  there  are  19 
marginal  plates  in  40  mm.].  The  marginal  pieces  seem  each  to 
connect  with  the  adjacent  range  of  dorsal  pieces,  at  places  in  the 
rays,  by  a  little  central  salient  point  only,  while  those  of  both  series 
are  roughened  by  numerous  comparatively  coarse  granules  [all  of 
which  bear  small  spines],  and  each  piece  (especially  [only]  of  the 
marginal  row)  also  shows  a  small  central  pit  for  the  articulation  of 
a  spine.  These  spines  are  larger  than  those  connected  with  the 
dorsal  pieces,  being  generally  about  0.22  inch  in  length  and  0.05  inch 
in  thickness;  they  are  smooth,  straight,  rounded,  slightly  thickened  at 
the  attached  end,  and  tapering  at  the  free  end  to  a  slightly  blunted 
point.  [The  adambulacral  plates  also  possess  these  large  spines, 
which  are  inserted  on  the  distal  inner  edge  of  each  plate.]" 

In  each  interbrachial  area  there  are  two  pairs  of  wedge-shaped 
pieces  and  a  single  diamond-shaped  interbrachial  marginal  plate. 
There  are  at  least  4  (and  may  be  as  many  as  10)  pairs  of  adam- 
bulacral plates  orally  or  in  the  actinal  interbrachial  areas,  the  terminal 
pair  being  of  the  oral  armature. 

Ambulacral  plates  much  wider  than  long,  increasing  rapidly  in 
width  toward  the  mouth.  Each  plate  is  carinated  as  in  P.  sped- 
osus  and  proximally  as  in  P.  magnificus,  with  the  podial  openings 
confined  to  the  extreme  outer  edge  of  the  ambulacral  furrows. 

Formation  and  locality. — Found  at  Cincinnati,  Ohio,  in  the  Mays- 
ville  beds,  about  200  feet  below  the  top  of  the  hills.  The ,holo type 
is  in  the  Dyer  collection  of  the  Museum  of  Comparative  Zoology, 
Harvard  University  (No.  13).  Another  specimen  from  near  the  top 
of  the  Maysville  at  Cincinnati,  preserving  only  the  disk  and  showing 
best  the  actinal  area,  is  in  the  Gurley  collection  of  the  University 
of  Chicago  (No.  10989).  Originally  this  individual  appears  to  have 
been  larger  than  the  holotype. 

Remarks. — The  relationship  of  this  species  is  with  P.  spinulosus, 
but  the  larger  size,  greater  development  of  both  dorsal  and  ventral 
spines,  absence  of  columnar  arrangement  of  the  abactinal  plates, 
and  the  presence  of  five  instead  of  two  or  three  interbrachial  marginal 
plates  will  readily  separate  P.  dyeri  from  the  latter  species.  Even 
though  this  form  appears  to  have  attained  a  larger  growth  than 
P.  magnificus,  which  it  resembles  in  some  characters,  it  differs  in 
being  more  ponderous  in  its  skeleton  and  in  the  far  stouter  and 
longer  actinal  spines. 

Regarding  the  generic  position  of  Palseaster  dyeri,  Meek  wrote: 

"  Possibly  I  should  have  called  it  Petraster  dyeri,  for  if  the  apparent 
presence  of  a  few  disk  plates  on  the  ventral  side  between  the  mar- 


122  BULLETIN    88,   UNITED    STATES    NATIONAL   MUSEUM. 

ginal  pieces  and  the  adambulacral,  is  not  deceptive,  it  would,  in 
that  respect,  conform  to  the  structure  of  that  group,  and  differ 
from  Palseaster,  as  now  understood;  though  I  am  inclined  to  think 
this  appearance  due  to  the  accidental  displacement  of  the  parts  at 
the  point  where  there  are  some  indications  of  a  few  disk  pieces." 
These  pieces  are  not  to  be  correlated  with  the  accessory  interbrachial 
plates  of  Petraster,  for  in  this  genus  accessory  plates  consist  of  two 
short  columns  situated  between  the  adambulacral  and  marginal 
plates  and  uniting  in  the  axillary  areas.  In  P.  dyeri,  however,  the 
four  interbrachial  marginal  plates  are  continuous  with  the  infra- 
marginal  columns  and  evidently  were  derived  from  that  series, 
and  are  not  accessory  interbrachials.  It  is  true  that  all  interbrachial 
plates  increase  the  size  of  the  disk,  but  in  one  they  are  derived  from 
the  inframarginal  series,  by  crowding  and  in  the  other  they  are 
interpolated,  newly  developed  plates  that  force  apart  the  columns 
of  plates  in  the  rays  sometimes  almost  to  the  distal  ends. 

PROMOPAL.EASTER  MAGNIFICUS  (Miller). 

Plate  21,  fig.  1;  plate  22,  fig.  1;  plate  23,  figs.  1-3. 

Palseaster  magnificus  MILLER,  Journ.  Cincinnati  Soc.  Nai.  Hist.,  vol.  7,  1884, 
p.  16,  pi.  4,  figs.  3,  3a. 

Original  description. — "The  diameter  or  breadth  of  the  disk  is 
one  and  one-fourth  niches,  and  the  distance  from  the  point  of  one 
ray  to  the  point  of  the  opposite  one,  if  the  rays  were  wholly  preserved 
in  the  specimen  under  examination,  would  be  fully  6  inches.  *  *  * 

"The  plates  upon  the  dorsal  side  are  very  convex,  and  part  of 
them,  at  least,  were  spine-bearing,  though  it  would  seem  that  there 
was  not  more  than  one  spine  upon  any  single  plate.  The  arrange- 
ment of  the  plates  on  the  dorsal  side  of  the  rays  is  very  ornamental. 
A  single  series  of  highly  convex  or  conical  plates,  larger  than  the 
others,  and  each  evidently  bearing  a  central  spine,  occupies  the 
middle  of  each  ray;  on  either  side  near  the  margin  of  each  ray  there 
is  a  similar  series,  and  the  two  intervening  spaces  are  filled  with 
smaller,  convex  plates  arranged  in  rows  which  are  directed  diagonally 
forward  from  the  plates  of  the  side  series  to  the  plates  of  the  central 
series,  forming  angles  with  each  plate  in  the  central  series  occupying 
an  angle.  This  disposition  of  the  plates  on  the  dorsal  side  of  the 
rays  will,  so  far  as  known,  serve  to  distinguish  this  species  from  any 
hitherto  described. 

"The  plates  covering  the  dorsal  side  of  the  body  or  disk  have  been 
so  much  disturbed  in  our  specimen  that  one  can  not  correctly  define 
them. 

"The  ambulacral  furrows  are  wide.  The  marginal  plates  are 
hexagonal,  about  the  size  of  the  larger  plates  on  the  dorsal  side  of 


KEVISION    OF   PALEOZOIC    STELLEKOIDEA.  123 

the  rays,  and  separated  from  the  side  series  by  intervening  smaller 
plates.  Each  bore  several  small  spines,  as  shown  by  the  small  pits 
for  their  articulation.  *  *  * 

"The  adambulacral  plates  are  hexagonal  and  much  wider  than 
long.  They  are  more  numerous  than  the  marginal  plates  near  the 
disk,  but  toward  the  apices  of  the  rays  they  interlock  alternately 
with  the  marginal  plates.  The  number  on  each  side  of  a  furrow  hi 
a  complete  ray  would  be  50  or  more.  The  pits  for  the  articulation 
of  the  spines  are  as  numerous  as  they  are  on  the  marginal  plates. 
These  two  series  on  the  ventral  side  of  the  species,  with  numerous 
spines  upon  each  plate,  are  in  striking  contrast  with  the  plates  on 
the  dorsal  side  of  the  rays,  where  no  plate  bears  more  than  a  single 
spine. 

"The  ambulacral  plates  have  their  greatest  length  across  the 
rays,  and  seem  to  be  about  as  numerous  as  the  adambulacral  ones. 
An  angular  depression  marks  the  center  of  each  ambulacral  furrow, 
upon  each  side  of  which  a  sharp  ridge  arises  upon  each  ambulacral 
plate,  and  curving  forward  and  outward  abuts  against  an  adambula- 
cral plate. " 

Emended  description. — The  largest  specimen,  the  holotype,  meas- 
ures R  =  (about)  67  mm.,  r  =  17  mm.,  R  =  nearly  4r.  Another  speci- 
men: 11  =  58  mm.,  3*  =15  mm.,  R=  nearly  4r. 

Abactinal  surface  very  ornamental.  Medially  along  each  ray  there 
is  a  radial  column  of  highly  convex  plates,  and  two  columns  of  similar 
plates,  the  supramarginals,  are  situated  near  the  margin.  Between 
the  inframarginal,  supramarginal,  and  radial  columns  are  very  nu- 
merous diagonal  rows  of  smaller  conical  or  angular  plates,  from  2  at 
the  apex  of  the  ray  to  14  at  base  of  same  in  each  row  on  each  side  of 
the  radial  column.  This  may  be  stated  in  another  way.  Between 
the  radial  and  supramarginal  columns  and  again  in  the  ambital  area, 
or  between  the  supramarginals  and  inframarginals,  the  diagonal  rows 
have  from  one  to  seven  plates  in  each  area.  These  rows  are  directed 
diagonally  and  distally  across  the  rays  from  the  sides  to  the  median 
column,  the  apex  of  the  angle  thus  formed  being  occupied  by  the 
larger  plates  of  the  radial  column.  All  of  these  smaller  plates  appar- 
ently bore  a  single  short  spine.  Between  all  of  the  diagonal  rows 
are  inserted  both  proximally  and  distally  numerous  minute,  conical, 
irregular-shaped  plates.  The  supramarginal  columns  continue  across 
the  disk  and  those  of  adjoining  rays  unite  in  the  axillary  areas.  The 
radial  columns  also  extend  over  the  disk  but  do  not  attain  the  center, 
and  the  diagonal  arrangement  of  the  small  plates  ceases  near  the 
proximal  portion  of  the  rays.  The  pattern  arrangement  of  the  disk 
plates  can  not  be  made  out  since  their  original  position  is  disturbed. 

Madreporite  quite  large,  quadri-lobate  in  outline,  depressed,  convex 
and  very  finely  radiately  striate.  It  is  situated  in  one  of  the  axillary 


124  BULLETIN   88,  UNITED   STATES   NATIONAL  MUSEUM. 

areas,  less  than  4  mm.  from  the  margin.  Against  it  rest  two  columns 
of  supramarginal  plates. 

The  inframarginal  plates,  of  which  there  are  at  least  45  in  each 
column,  are  distally  small  and  subquadrate  but  proximally  increase 
rapidly  in  size  and  at  the  base  of  the  columns  are  three  to  four  times 
as  wide  as  long.  These  plates  bear  numerous  pitted  pustules  upon 
which  articulated  short,  sharp,  smooth  spines.  The  columns  of  ad- 
joining rays  meet  in  the  axils  and  continue  into  the  interbrachial 
areas. 

The  adambulacral  plates  are  like  the  inframarginals  but  do  not 
increase  so  rapidly  in  width  as  those  plates  and  are  somewhat  more 
numerous,  there  being  in  a  complete  ray  about  52  in  a  column. 
Proximally  some  of  the  large  plates  are  broken  into  two  or  three 
often  very  convex  ossicles.  In  addition  to  the  small  spines  like  those 
of  the  inframarginals,  each  plate  bears  on  its  ambulacral  edge  a  prom- 
inent socket  in  which  articulated  a  long,  thick,  smooth  spine.  The 
adambulacral  plates  in  the  proximal  third  of  the  rays  each  have  a 
small,  more  or  less  wedge-shaped,  carinated,  accessory  adambulacral 
plate.  In  this  region  these  ossicles  separate  the  adambulacrals  from 
the  ambulacrals  and  beneath  the  accessory  adambulacral  plates  are 
the  podial  openings.  Five  or  six  adambulacral  plates  of  each  column 
abut  against  the  interbrachial  marginal  plates,  while  five  or  six  pairs 
continue  orally,  the  terminating  pieces  being  of  the  oral  armature. 

Ambulacral  furrows  wide,  increasing  in  width  proximally.  An 
angular  median  sinus  marks  each  ambulacral  furrow.  Ambulacral 
plates  short  but  wide,  slightly  overlapping  proximally,  and  one  to 
each  adambulacral  plate.  All  of  the  plates  are  strongly  carinated, 
the  carina  in  the  distal  two-thirds  converging  medially  and  proximally. 
In  the  proximal  third  the  carinse  gradually  are  changed  in  form  and 
are  there  arranged  in  forked  pairs.  In  other  words,  the  carinae  adjoin 
the  accessory  adambulacrals,  are  arranged  in  pairs,  continuing  ad- 
joining and  straight  for  a  short  distance,  and  then  diverge  in  broad 
curves,  terminating  near  the  center  of  the  ambulacral  groove.  This 
arrangement  produces  in  the  proximal  portion  of  the  ambulacral 
furrows  four  columns  of  ovoid  pits,  all  terminating  laterally  into 
podial  openings.  Every  other  podial  opening  belongs  to  the  same 
column,  one  series  beneath  the  adambulacrals,  the  other  gradually 
passing  medially  in  the  ambulacral  grooves.  In  the  distal  two-thirds, 
however,  the  podial  openings  are  arranged  in  single  columns,  one  to 
each  ambulacral  plate  and  issuing  from  underneath  the  adambulacrals. 

Interbrachial  areas  with  seven  plates,  each  composed  of  two  prox- 
imal inframarginals,  beneath  which  are  two  pairs  of  interbrachial 
marginals  and  a  single  diamond-shaped  axillary  marginal  plate.  All 
bear  similar  spines  and  ornamentation  on  the  inframarginals.  Some- 
times one  of  the  distal  interbrachial  marginals  may  be  divided  and 


REVISION    OF   PALEOZOIC    STELLEEOIDEA.  125 

the  arrangement  of  the  interbrachial  plates  made  irregular.  In  a 
specimen  from  Jefferson  County,  Indiana,  there  are  3  pairs  of  inter- 
brachial marginals  instead  of  2  as  in  the  Ohio  individuals.  There- 
fore there  are  also  more  adambulacrals  here,  14  pairs  against  10  in 
the  typical  specimens. 

Formation  and  locality.  —  Two  free  specimens  of  this  magnificent 
starfish  were  found  in  the  Richmond  formation  near  Waynesville, 
Ohio.  Originally  pieces  of  these  two  individuals  were  glued  together 
as  one  specimen,  which  is  the  cause  of  our  figures  being  less  perfect 
than  Mr.  Miller's.  Fragments  of  seven  other  individuals  were  found 
in  the  vicinity  of  Waynesville.  In  the  University  of  Chicago  col- 
lection (No.  10981)  there  is  a  specimen  from  Jefferson  County, 
Indiana,  apparently  of  this  species.  Mr.  Vaupel  secured  the  distal 
portion  of  a  ray  of  an  apparently  young  example  of  this  species  in 
the  Maysville  beds  on  Rons  Hill,  Cincinnati,  Ohio,  and  Mr.  Ulrich 
has  fragments  of  four  individuals  from  the  Maysville  strata  about 
Cincinnati,  and  Covington,  Kentucky. 

Remarks.  —  This  species  is  readily  separated  from  the  other  species 
of  Promopalxaster  by  the  marked  diagonal  rows  of  abactinal  plates. 
Actinally  P.  magnificus  is  readily  distinguished  from  P.  exculptus  and 
P.  spinosus  in  having  five  instead  of  three  interbrachial  marginal 
plates  in  each  area,  in  the  rapidly  increasing  size  of  the  plates  in  the 
inframarginal  and  adambulacral  columns,  and  in  the  proximal  am- 
bulacral  plates.  P.  speciosus  differs  at  once  from  P.  magnificus  in  that 
its  abactinal  plates  are  arranged  in  regular  longitudinal  columns, 
are  far  less  numerous,  larger  and  are  all  nearly  of  a  size. 

This  is  one  of  the  largest  and  best  preserved  of  American  Paleozoic 
starfishes.  P.  dyeri  may  be  a  larger  species  but  is  distinguished  abac- 
tinally  not  only  by  the  arrangement  and  difference  in  the  forms  of 
the  plates  but  also  by  the  short,  thick,  blunt  spines  which  now  ap- 
pear to  have  no  definite  arrangement,  while  P.  magnificus  has  all  of 
its  very  fine  spines  arranged  in  diagonal  rows  like  the  plates. 

Cat.  Nos.  40883,  60621,  60622,  U.S.N.M. 


new    subfamily. 

Aberrant  Promopalaeasteridae  with  the  axillary  and  interbrachial 
areas  composed  entirely  of  adambulacral  pieces. 
Contains  : 
Anorihaster. 

ANORTHASTER,    new  genus. 

Plate  13,  fig.  4;  plate  20,  fig.  1. 
Anorthaster  SCHUCHERT,  Fossilium  Catalogus,  Animalia,  pt.  3,  April,  1914,  p.  11. 

A  +  orihos  +  aster  =  out  of  the  regular,  in  reference  to  the  completely 
adambulacral  na-ture  of  the  interbrachial  areas. 


126  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

Generic  characters. — Disk  small,  with  apparently  small  interbrachial 
arcs.  Rays  five,  of  moderate  length  and  tapering  at  first  slowly 
and  then  rapidly  distally. 

Abactinai  area  unknown. 

Inframarginal  plates  small,  the  columns  not  attaining  the  axils, 
but  resting  upon  the  second  enlarged  axillary  adambulacral  plate. 

Adambulacral  plates  distally  like  the  inframarginals,  increasing 
in  size  slowly  proximally  until  near  the  axillary  region,  where  four 
plates  suddenly  attain  great  width,  terminating  in  the  axils  of  the 
rays  and  here  suppressing  the  inframarginal  plates.  Eight  inter- 
brachial adambulacrals  of  varying  form  are  situated  orally  to  the  two 
large  axillary  adambulacral  plates,  and  at  first  give  one  the  impression 
of  slender  interbrachial  areas  of  the  same  nature  as  in  Promopalszaster. 
These  plates,  however,  are  not  interbrachial  marginals,  as  in  other 
genera,  and  derived  by  the  oral  crowding  of  proximal  inframarginals. 
They  are  distinctly  adambulacral  ossicles,  forming  slight  interbrachial 
areas,  and,  with  the  axillary  adambulacrals,  form  small  arcs.  For  the 
shape  and  position  of  these  plates  see  figure  1,  plate  20. 

Ambulacral  plates  alternating,  slightly  carinated,  and  very  short 
but  wide.  In  the  distal  region  they  are  as  long  as  the  adambulacral 
plates,  but  proximally  decrease  in  length  where  there  are  nearly  two 
of  them  to  one  adambulacral  ossicle.  Podial  openings  between  every 
other  plate  through  the  sutures  of  adjoining  pieces  at  their  outer 
edge  and  immediately  beneath  the  inner  edge  of  the  adambulacral 
ossicles.  The  proximal  plates  of  each  column  are  modified  into  oral 
armature  pieces  that  are  slightly  tumid,  as  long  as  wide,  and  sub- 
triangular  in  outline.  Between  the  proximal  ambulacrals  and  orad 
to  the  proximal  interbrachial  adambulacrals  are  situated  additional 
single,  very  small,  quadrangular  oral  armature  plates. 

Genoholotype  and  only  species. — Palseaster  miamiensis  Miller. 

Distribution. — Ordovicic,  Richmond  formation,  near  Waynesville, 
Ohio. 

Remarks. — The  suppression  of  the  inframarginal  plates  in  the  axils 
of  the  rays  by  two  of  the  adambulacral  plates  of  each  column  and 
the  oral  continuation  beneath  the  latter  of  four  pairs  of  adambulacral 
plates  holding  an  interbrachial  position  distinguish  this  genus 
fromPromopalseaster,  to  which  it  otherwise  seems  very  closely  related. 
This  character  also  distinguishes  it  from  all  other  associated  genera. 

The  interbrachial  structure  of  Anorthaster  appears  abnormal.  In 
Mesopalseaster  and  Promopalseaster  the  proximal  inframarginal  plates 
are  crowded  orally  and  form  interbrachial  areas;  in  Anorthaster  their 
formation  is  effected  in  the  opposite  way,  not  by  the  inframarginals, 
but  by  the  adambulacrals.  This  character  is  seen  in  a  single  speci- 
men, but  it  is  so  regularly  developed  and  well  preserved  as  to  indicate 
a  normal  and  not  a  pathologic  or  abnormal  condition. 


KEVISION    OF   PALEOZOIC    STELLEROIDEA.  127 

ANORTHASTER  MIAMIENSIS  (Miller). 

Plate  13,  fig.  4;  plate  20,  fig.  1. 

Palseaster  miamiemis  MILLER,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  3,  1880, 
p.  143,  pi.  4,  fig.  3. 

Original  description. — "  Pentagonal;  rays  about  one  and  a  half 
times  the  diameter  of  the  body,  or  about  nine-tenths  of  an  inch; 
diameter  of  the  body  about  six-tenths  of  an  inch;  breadth  of  a  ray 
at  the  point  of  junction  with  the  body  a  little  more  than  half  the 
diameter  of  the  body,  or  about  seven-twentieths  of  an  inch;  rays 
obtusely  pointed. 

"Marginal  plates  wider  than  long,  and  numbering  about  12  in 
the  length  of  half  an  inch  from  the  body.  Two  marginal  plates 
form  the  junction  of  the  rays.  Ambulacral  furrow  wide,  the  plates 
being  more  than  twice  as  long  as  wide.  There  are  about  18  ambu- 
lacral  plates  in  a  length  of  one-half  inch,  and  each  one  is  provided 
with  an  angular  ridge  taperingfrom  the  marginal  plates  to  the  furrow." 

Emended  description.— R  =  23  mm.,  r  =  7  mm.,  R  =  3.2r.  Width  of 
rays  at  base  8  mm. 

Rays  tapering  very  slowly  in  the  proximal  half,  but  more  rapidly 

distally. 

Abactinal  area  unknown. 

Inframarginal  plates  about  16  in  each  column  and  subquadr angular 
in  outline.  These  ossicles  do  not  continue  into  the  axils,  but  rest 
upon  the  second  large  axillary  adambulacral  plate. 

Adambulacral  plates  about  18  in  each  column,  like  the  infra- 
marginal  pieces,  increasing  in  size  proximally,  while  the  two  axillary 
ones  are  suddenly  enlarged,  extend  to  the  margin  of  the  disk,  and  have 
the  position  of  marginal  ossicles.  Orally  to  the  latter  the  adambu- 
lacral plates  continue  as  interbrachial  ossicles.  The  distal  pair  is 
large  and  both  are  wedge-shaped,  followed  by  two  pairs  of  quite 
small  quadrangular  plates  and  a  final  pair  of  long  and  narrow  plates; 
in  all  there  are,  therefore,  22  adambulacral  plates  in  each  column. 
The  interbrachial  adambulacral  plates  are  terminated  by  a  single 
quadrangular  oral  plate  wedged  in  between  the  proximal  ambu- 

a  ILbulacral  furrows  very  wide,  broadly  gutter-shaped.  Ambu- 
lacral plates  about  30  in  a  column,  slightly  alternating,  decidedly 
wider  than  long  proximally,  increasing  in  length  distally,  and  finally 
becoming  about  as  wide  as  long  near  the  apex  of  a  ray.  Each  plate 
is  slightly  carinated,  the  ridges  crossing  the  plates  from  the  lateral 
distal  edge  to  the  medial  proximal  edge.  The  proximal  ambulacral 
plates  are  modified,  conspicuous,  and  subtriangular  in  outline 
Podial  openings  between  two  adjoining  plates  in  alternate  sutures  at 

50601°— Bull.  88—15 9 


128  BULLETIN-   88,   UNITED   STATES   NATIONAL   MUSEUM. 

their  extreme  outer  edges  and  immediately  inside  of  the  adambu- 
lacral  plates. 

Formation  and  locality. — In  the  Richmond  formation,  near  Waynes- 
ville,  in  Montgomery  County,  Ohio.  The  holotype  is  in  the  Harris 
collection  of  the  United  States  National  Museum. 

Eemarks.—  -This  species  has  a  general  resemblance  to  some  of  the 
Promopalseasters,  particularly  P.  ~bellulus  and  P.  wylcoffi,  but  the 
peculiar  arrangement  of  the  axillary  and  interbrachial  adambulacral 
plates  will  distinguish  it  not  only  from  them  but  from  all  other 
Ordovicic  asterids. 

Cat.  No.  40880,  U.S.N.M. 

Family  XENASTERID^E  Schondorf. 

Xenasteridx  GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6, 1899,  p.  346;  Treat.  Zool.,  vol.  3, 

Echinoderma,  1900,  p.  250. 

Palsegoniasteridse  STURTZ,  Palaeontographica,  vol.  36,  1890,  p.  247  (not  opp.  246). 
Xenasteridse  SCHONDORF,  Palaeontographica,  vol.  56,  1909,  p.  105;  Jahrb.  nassau- 

isch.  Ver.  Naturk.,  Wiesbaden,  vol.  62,  1909, p.  25;  vol.  63, 1910,  pp.  244,  250. 

Progressive  Phanerozonia  having  the  general  characters  of  the 
Promopalseasterinse,  with  the  addition  of  accessory  interbrachials. 
The  ambulacral  and  adambulacral  plates  are  directly  opposite  one 
another  and  do  not  waver  between  the  slightly  alternate  and  opposite 
arrangement  in  the  Promopalaeasteringe.  Podial  openings  in  two 
columns  in  each  ambulacral  furrow,  the  apertures  lying  between 
each  four  adjoining  plates,  that  is,  between  two  adambulacrals  and 
two  ambulacrals. 
Contains : 

Xenaster  Simonovitsch. 

Agalmaster  Schondorf. 

Khenaster  Schondorf. 

Eifelaster  Schondorf. 

Trimeraster  Schondorf. 

Schondorf  defines  the  family  as  follows  (leaving  out  much  of  his 
detail)  : 

Lower  Devonic  starfishes  with  well-developed  supramarginals  and 
usually  still  larger  inf  ramarginals ;  the  latter  are  somewhat  more  numer- 
ous than  the  former,  causing  them  to  be  unequally  superposed.  Ambu- 
lacra opposite  one  another  and  opposite  the  adambulacrals;  podial 
openings  in  two  rows.  Actinally  each  interradius  has  either  three  or 
five  interbrachial  plates;  abactinally  this  area  is  filled  with  small 
accessory  plates  and  margined  only  by  inframarginals.  Disk  skeleton 
consisting  of  small  separated  pieces,  a  central  disk  plate,  five  primary 
radialia,  five  primary  interradialia,  and  more  or  less  of  accessory  disk 


KEVISION   OF   PALEOZOIC   STELLEEOIDEA.  129 

ossicles.  Eays  with  three  columns  of  plates,  one  radial  and  two 
supramarginal,  that  may  or  may  not  be  separated  from  one  another 
by  small  accessory  pieces.  Madreporite  dorsal  and  interradial. 

Genus  XENASTER  Simonovitsch  emend.  Sehondorf. 

Plate  24. 

Archseasterias  MULLER,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  12, 1855,  pp. 
6,  8  (Archxasterias  founded  in  error). 

Xenaster  SIMONOVITSCH,  Sitzb.  mat.-naturw.  Classe  Akad.  Wiss.,  Wien.  vol.  64, 
Abt.  1,  1871,  p.  88.— SCHONDORF,  Palseontographica,  vol.  56,  1909,  pp.  42, 
105  (complete  synonymy  given  here);  Jahrb.nassauisch.  Ver.  Naturk.,  Wies- 
baden, vol.  62,  1909,  p.  26. 

Generic  characters. — Xenaster  has  its  nearest  relationship  in 
Devonaster.  No  detailed  description  need  be  given,  since  the  splendid 
illustrations  of  Sehondorf  give  all  the  necessary  characters.  It 
differs  from  Devonaster  as  follows: 

In  Devonaster  there  is  but  a  single  interbrachial  plate  in  each 
actinal  axil,  the  axillary  interbrachial,  while  in  Xenaster  there  are 
two  pairs  of  interbrachial  marginals  and  a  single  axillary  inter- 
brachial plate;  in  other  words,  five  interbrachial  plates  instead  of 
one  (1+2+2).  In  addition  to  these  plates  in  Xenaster,  the  interbra- 
chials  are  more  or  less  surrounded  by  small  accessory  pieces,  and  then 
other  similar  plates  separate  the  inf  ramarginal  and  adambulacral  col- 
umns to  near  the  outer  third  of  the  rays.  The  inf  ramarginal  plates  in 
Xenaster  do  not  increase  so  rapidly  in  width  proximally  as  do  these 
plates  in  Devonaster,  and  while  the  interbrachial  areas  are  of  about 
the  same  size  in  both  genera,  the  space  occupied  by  the  additional 
interbrachial  marginal  and  accessory  interbrachial  ossicles  in  the 
former  is  taken  up  in  the  latter  genus  by  the  increased  size  of  the 
inf  ramarginal  pieces. 

Abactinally  Xenaster  has  the  generic  characters  of  Devonaster. 
The  plates  in  all  the  columns  of  the  former  genus  are  more  prominent 
and  rounder,  particularly  the  accessory  plates,  of  which  there  appear 
to  be  less  than  in  Xenaster.  The  center  of  the  disk  in  both  genera 
is  occupied  by  a  small  central  disk  plate,  but  there  are  many  more 
accessory  plates  around  it  in  Devonaster  than  in  Xenaster.  In  both 
genera  the  supramarginal  columns  converge  proximally,  producing 
small  disk  areas  between  the  infra-  and  supramarginal  plates  occu- 
pied by  ambital  accessory  plates. 

Madreporite  large  and  striate  in  Xenaster. 

Genotype. — X.  margaritatus  Simonovitsch. 


130  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

Distribution. — Restricted  to  the  Lower  Devonic  of  Germany. 
The  species  are: 

X.  margaritatus  Shnonovitsch. 

X.  dispar  Schondorf. 

X.  elegans  Schondorf. 

X.  (?)  rhenanus  (Miiller). 

Remarks. — Miiller  in  his  description  of  Asterias  rtienana,1  the  geno- 
type of  Archseasterias ,  notes  that  the  adambulacral  plates  of  adjoining 
columns  alternate  and  that  the  ambulacral  columns ' '  have  the  appear- 
ance also  of  alternating/'  which  if  established  would  be  very  remark- 
able, and  would  justify  the  creation  of  a  distinct  genus  Archseasterias 
for  this  asterid  of  the  Rhine  grauwacke.  Schondorf  shows  that 
these  statements  of  Miiller' s  are  very  faulty  and  further  that  the 
genus  Archseasterias  has  not  been  denned  so  as  to  be  recognizable. 
Under  these  circumstances  it  was  best  for  Simonovitsch  to  disre- 
gard Archseasterias  and  to  establish  a  new  generic  name  for  his  species 
margaritatus.  There  is  no  Paleozoic  genus  of  starfishes  better 
described  or  illustrated  than  this  one  by  Simonovitsch,  and  should 
it  ever  prove  that  Asterias  rhenana  Miiller  is  identical  with  Xenaster 
margaritatus,  a  possibility,  the  latter  should  not  be  made  to  give 
way  to  the  former  on  the  ground  of  priority.  It  is  an  injustice  to 
extend  the  law  of  priority  indiscriminately  to  all  work,  and  to  reject 
Archseasterias  is  no  reflection  on  the  work  of  Miiller,  as  his  material 
was  very  poor  and  his  work  of  early  date  in  paleontology.  He  pub- 
lished at  a  time  when  it  was  very  desirable  to  learn  anything  what- 
ever about  Paleozoic  starfishes. 

As  pointed  out  above,  Xenaster  has  much  of  the  structure  of 
Devonaster,  yet  it  differs  in  the  important  character  of  having 
numerous  accessory  interbrachial  plates.  This  feature  seemingly 
relates  it  with  forms  like  Palasterina  which  have  a  great  abundance 
of  accessory  interbrachials,  yet  in  no  interbrachial  area  of  this  genus 
are  there  axillary  interbrachials  or  interbrachial  marginals.  In  other 
words,  the  Palasterina  type  of  disk  is  made  by  the  intercalation  of 
accessory  plates  between  the  inframarginals  and  adambulacrals, 
whereas  hi  Devonaster  it  is  accomplished  by  the  greater  width  of  the 
inframarginals  and  by  the  oral  crowding  of  a  plate  which  in  primitive 
forms  is  an  axillary  marginal.  Devonaster  although  from  younger 
strata  is  more  primitive  than  Xenaster  because  of  its  simpler  inter- 
brachial actinal  structure.  If  it  were  not  for  the  accessory  inter- 
brachials, Xenaster  would  be  closely  related  to  Promopalseaster  which 
also  has  a  number  of  proximal  inframarginals  crowded  into  the  inter- 
brachial areas.  It  is  the  Promopalseaster  stock  out  of  which  Xenaster 
probably  developed,  while  Devonaster  apparently  came  through 
Mesopalseaster. 

*  Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  12, 1855,  pp.  6,  8. 


REVISION"   OF  PALEOZOIC   STELLEROIDEA.  131 

XENASTER  MARGARITATUS  Simonovitsch  emend.  Schondorf. 

Plate  24,  figs.  1,2. 

Xenaster  margaritatus  (part)  SIMONOVITSCH,  Sitzb.  mat.-naturw.  Classe  Akad. 
Wiss.,  Wien,  vol.  64,  Abt.  1,  1871,  p.  88,  pis.  1,  2.— SCHONDORF,  Palseon- 
tographica,  vol.  56,  1909,  pp.  43,  106,  pi.  7,  figs.  1,  3,  4;  pi.  8,  fig.  1;  pi.  11, 
figs.  2,  3,  10,  11  (complete  synonymy  given  here);  Jahrb.  nassauisch.  Ver. 
Naturk.,  Wiesbaden,  vol.  62,  1909,  p.  26,  pi.  2,  figs.  1,  2.— SPENCER,  Mon. 
Brit.  Pal.  Asterozoa,  pt.  1  (Palaeontogr.  Soc.  for  1913),  1914,  p.  30. 

This  species  is  one  of  the  best  described  and  illustrated  of  Paleozoic 
starfishes  and  does  credit  to  its  author,  and  to  its  subsequent  reviser, 
Schondorf.  It  occurs  rarely  in  the  Lower  Devonic  (Upper  Coblen- 
zian)  as  natural  molds  at  Niederlahnstein  on  the  Rhine,  Germany. 

XENASTER  DISPAR  Schondorf. 

Xenaster  margaritatus  (part)  SIMONOVITSCH,  Sitzb.  mat.-naturw.  Classe  Akad. 

Wiss.,  Wien,  vol.  64,  1871,  Abt.  1,  pi.  2,  figs.  2,  2a,  26. 
Xenaster  dispar  SCHONDORF,  Palaeontographica,  vol.  56,  1909,  pp.  50,  84,  106, 

pi.  9,  fig.  1;  pi.  11,  fig.  13;  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol. 

62,  1909,  p.  28,  pi.  3,  fig.  3. 

From  the  Upper  Coblenzian  at  Niederlahnstein,  and  Miellen, 
Germany. 

XENASTER  ELEGANS  Schondorf. 

Xenaster  margaritatus  FOLLMANN  (not  Simonovitsch) ,  Jahrb.  naturh.  Ver.  preuss. 

Rheinl.,  etc.,  vol.  48,  1891,  p.  150. 
Xenaster  elegans  SCHONDORF,  Palseontographica,  vol.  56,  1909,  pp.  53,  107,  pi.  9, 

figs.  2,  3;  pi.  11,  figs.  4, 12;  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol. 

62,  1909,  p.  40,  pi.  4,  figs.  6,  7. 

From  the  Lower  Devonic  (Coblenz  quartzite)  at  Konigstuhl,  near 
Rhens,  Germany. 

XENASTER  (?)  RHENANUS  (Muller). 

Asterias  (Archseasterias}  rhenana  MULLER,  Verh.  naturh.   Ver.  preuss.  Rheinl., 

etc.,  vol.  12,  1855,  p.  6,  pi.  1,  figs.  4-6. 
Xenaster  (?)  rhenana  SCHONDORF,  Palaeontographica,  vol.  56,  1909,  pp.  55,  107, 

text  fig.  2  (complete  synonymy  given  here);  Jahrb.  nassauisch.  Ver.  Naturk., 

Wiesbaden,  vol.  62, 1909,  p.  28. 

This  species  is  based  upon  incomplete  material  and  can  not  be 
made  out  fully.  It  seems  probable  that  it  is  a  species  of  Xenaster 
and  closely  related  to  X.  margaritatus  Simonovitsch.  The  examples 
are  in  the  Berlin  Museum  and  were  found  in  the  Lower  Devonic  at 
Winningen,  near  Coblenz,  and  Kemmenau,  near  Ems,  Germany. 

Genus  AGALMASTER  Schondorf. 

Text  fig.  9. 

Agalmaster  SCHONDORF,  Palseontographica,  vol.  56,  1909,  pp.  58,  107;  Jahrb. 
nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  62,  1909,  p.  29. 

Original  remarks. — Agalmaster  differs  from  Xenaster  in  the  following 
characters:  Forms  larger,  broader  rayed,  with  flat  actinal  but  highly 
arched  abactinal  plates.  Supramarginals  much  stronger  than  the 
large  inframarginals  and  projecting  considerably  beyond  these. 


132  BULLETIN  88,  UNITED  STATES  NATIONAL  MUSEUM.. 


\ 


Abactinal  interbrachial  area  small,  and  occupied  in  the  main  by  two 

axillary  inf  ramarginals  ;  actinally  this  area  has  the  same  structure  as 

Xenaster.     Madreporite  dorsal. 

Genoholotype  (the  writer  here  selects  the  first  species).  —  A.  miel- 

lensis  Schondorf.     Other  species  are  A.  grandis  Schondorf  and  A. 

intermedius  Schondorf,  both  from  the  Lower  Devonic  of  Germany. 
/  \  Remarks.  —  The   only 

/  \  character  that  may  be 

of  generic  value  and 
that  at  present  distin- 
guishes Agalmaster  from 
Xenaster  is  that  in  the 
former  genus  the  supra- 
marginals  margin  the 
rays  instead  of  the  in- 
f  ramarginals,  as  is  the 
case  in  the  latter  genus. 
In  a  second  species  (A. 
grandis)  the  small  ac- 
cessory interbrachials 
crowd  in  between  all  the 
pairs  of  interbrachial 

FIG.  9.—  AGALMASTER  MIELLENSIS,  AFTER  SCHONDORF.  SCHEMATIC   marginals  and     further 

ARRANGEMENT  OF  ABACTINAL  PLATES.     R*     AND  -R3,  SECOND  AND        ,  .  ' 

THIRD  PROXIMAL  RADIAUA;    Jn,  PRIMARY    INTERRADIALIAJ    Cdp,      tllCre    &TQ     J&T     ID.OTG     OI 

CENTRAL  PLATE;    mdp,  MADREPORITE;   mo,  SUPRAMARGINALIA;    ^ggQ    pieces    between 
mu,  INFRAMARGINALIA;  Pifm,  PRIMARY  INTERRADIALIA. 

the  inframargmals  and 

adambulacrals;  in  fact,  there  are  three  to  four  columns  of  these  in- 
stead of  one  (as  in  A.  mieUensis). 

AGALMASTER  MIELLENSIS  Schdndorf. 

Text  fig.  9. 

Agalmaster  mieUensis  SCHONDORF,  Palseontographica,  vol.  56,  1909,  pp.  58,  107, 
text  fig.  3;  pi.  8.  fig.  4;  pi.  9,  fig.  4;  pi.  11,  figs.  1,  5;  Jahrb.  nassauisch.  Ver.' 
Naturk.,  Wiesbaden,  vol.  62,  1909,  p.  29,  pi.  3,  fig.  2;  pi.  4,  figs.  1,  2. 

A  single  specimen  with  the  rays  about  43  mm.  long  was  found  in  the 
Lower  Devonic  (Upper  Coblenzian)  at  Miellen-on-the-Lahn,  Germany. 

AGALMASTER  GRANDIS  Schdndorf. 

Xenaster  margaritatus  SIMONOVITSCH  (part),  Sitzb.  mat.-naturw.  Classe  Akad. 

Wiss.,  Wien,  vol.  64,  Abt.  1,  1871,  pi.  2,  figs.  3,  3a. 
Agalmaster  grandis  SCHONDORF,  Palseontographica,  vol.  56,  1909,  pp.  62,  108, 

pi.  9,  fig.  5;  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  62,  1909,  p.  29, 

pi.  3,  fig.  1. 

One  specimen  (Xenaster  margaritatus  Simonovitsch,  part)  from 
the  Lower  Devonic  (Upper  Coblenzian)  at  Niederlahnstein  on  the 
Rhine,  Germany. 


REVISION   OF  PALEOZOIC   STELLEROIDEA. 


133 


AGALMASTER  INTERMEDIUS  Schflndorf. 

Agalmaster  intermedius  SCHONDORF,  Palaeontographica,  vol.  56,  1909,  pp.  82, 
108,  pi.  11,  fig.  14;  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  62, 
1909,  p.  30. 

From  the  Upper  Coblenzian  at  Miellen-on-the-Lahn,  Germany. 

Genus  RHENASTER  Sehondorf. 
Text  fig.  10. 

Rhenaster  SCHONDORF,  Palseontographica,  vol.  56,  1909,  pp.  65,  108,  pi.  8,  fig.  3; 
pi.  10,  figs.  1,  4. 

Remarks. — Rhenaster  is  a  small  form  and  differs  from  Xenaster, 
Agalmaster,  and  Devonaster  in  the  complete  absence  of  all  abactinal 
accessory  plates,  allow- 
ing the  radial  and  supra- 
marginal  pieces  to  ad- 
join one  another  closely. 
Dorsal  axillary  disk  ~7=TP?^©O g V\C\ 

T  i  I      /I        )s~*\-/    sr?~^   ^-'  /\S.       \V£ 

areas  not  completely 
but  almost  absent, 
supramarginals  in  the 
main  lying  wholly  upon 
the  inframarginals  and 
the  two  columns  of 
plates  together  margin- 
ing the  rays.  There 
also  are  no  accessory 
plates  of  any  kind  on 
the  actinal  side.  Other- 
wise the  generic  struc- 
ture is  that  of  Xenaster,  except  that  in  Rhenaster  the  first  pair  of 
interbrachial  marginals  are  not  yet  pushed  so  much  orally  and  they 
almost  take  part  in  margining  the  axils.  Madreporite  unknown. 

Genoholotype  and  only  species  (one  specimen). — R.  schwerdi  Schon- 
dorf,  from  the  Lower  Devonic  (Upper  Coblenzian)  at  Dorrbachtal, 
near  Coblenz,  Germany. 

Genus  EIFELASTER  Sehondorf. 

Etfelaster  SCHONDORF,  Palaeontographica,  vol.  56,  1909,  pp.  70, 108,  pi.  10,  figs. 

7,8. 

Remarks. — This  genus  is  very  closely  related  to  Rhenaster  and 
differs  only  in  that  there  are  small  dorsal  interbrachial  areas  between 
the  adjoining  proximal  portions  of  the  supramarginal  columns,  and 
these  are  filled  with  a  small  number  of  accessory  ambital  pieces. 
The  outer  portion  of  these  ambital  areas  is  made  up  of  the  two  basal 
inframarginals  that  occupy  the  axils  of  the  ventral  side. 


FIG.  10.— REENASTER  SCHWEKDI,  AFTEK  SCHONDORF.    SCHEMATIC 
ARRANGEMENT  OF  ABACTINAL  PLATES.    SYMBOLS  AS  IN  FIG.  9. 


134  BULLETIN   88,  UNITED   STATES  NATIONAL  MUSEUM. 

The  genoholotype  and  only  species,  E.  fottmanni,  occurs  in  the 
Lower  Devonic  (Lower  Coblenzian)  at  Landscheid,  near  Wittlich, 
in  the  Eifel,  Germany.  Plastotypes  of  the  holotype  were  made  for 
the  writer  by  Professor  Jaekel,  of  Greifswald,  and  these  are  now  in 
the  Yale  University  collection. 

Genus  TRIMERASTER  Schondorf. 

Plate  19,  fig.  1. 

Trimeraster  SCHONDORF,  Palaeontographica,  vol.  56,   1909,  pp.  68,  108,  pi.  7, 
fig.  2;  pi.  10,  figs.  5,  6. 

Remarks. — Trimeraster  is  a  small  form,  very  closely  related  to 
Xenaster,  and  can  be  distinguished  generically  only  in  that  the  former 
has  inside  of  the  inframarginals  but  one. pair  of  interbrachial  margi- 
nals and  a  single  axillary  interbrachial  in  each  interbrachial  field 
instead  of  the  five  plates  of  the  latter  genus. 

Genoholotype  and  only  species  (one  specimen). — T.  parvulus  Schon- 
dorf, from  the  Lower  Devonic  (Coblenz  quartzite)  at  Konigstuhl, 
near  Khens,  Rhine  Valley,  Germany. 

NEOPAL^ASTERIDJE,  new  family. 

Progressive  Phanerozonia  without  interbrachial  arcs.  The  columns 
of  supra-  and  inframarginal  plates  wholly  superposed.  Madreporite 
abactinal.  Well-developed  ocular  plates  present.  Ambulacrals  alter- 
nating. Disk  with  a  ring  of  large  plates  of  basal,  radial,  and  inter- 
radial  ossicles. 

Contains : 

Neopalseaster,  new  genus. 

The  origin  of  this  family  is  uncertain,  but  it  seems  to  be  related  to 
the  Promopalseasteridse,  since  its  essential  characters  are  those  of  the 
Mesopalaeasterinse.  In  the  latter  the  supramarginals  do  not  com- 
pletely overlie  the  inframarginals  making  one  consolidated  column  as 
in  Neopalseaster.  It  is,  so  far  as  known,  the  oldest  family  developing 
ocular  plates.  This  fact  is  of  considerable  importance  for  it  means 
that  the  oculars  were  originally  basal  radialia,  and  that  they  have 
progressively  wandered  from  the  disk  and  then  remained  at  the  tip 
of  the  rays. 

NEOPALSEASTER,  new  genus. 

Plate  13,  fig.  5;  pi.  23,  fig.  4. 
Neopalseaster  SCHUCHERT,  Fossilium Catalogue,  Animalia,  pt.  3,  April,  1914,  p.  26. 

Generic  characters. — Disk  of  medium  size,  without  interbrachial 
arcs.  Eays  five,  short  and  tapering  rapidly. 

Abactinally  the  disk  has  a  small  central  plate  surrounded  by 
numerous  smaller  plates.  Bounding  the  smaller  accessory  disk 


KEVISION   OF  PALEOZOIC   STELLEEOIDEA.  135 

plates  is  a  ring  of  very  large,  thick,  tumid,  variously  shaped,  radial 
and  interradial  plates.  Of  the  latter  there  may  be  one  plate  inside 
of  the  basal  supramarginals  of  adjoining  columns,  or  this  plate  may 
be  divided,  when  the  pieces  appear  as  inwardly  crowded  supramar- 
ginals. Laterally  and  distally  upon  the  interradials  are  situated  the 
large  basal  radial  plates.  The  rays  are  bounded  laterally  by  columns 
of  large,  thick,  subquadrate,  tubercular  supramarginals  terminated  dis- 
tally by  single  ocular  plates.  These  plates  appear  to  be  common  to 
both  the  actinal  and  abactinal  areas  and  must  therefore  be  the  united 
infra-  and  supramarginal  columns.  Between  the  supramarginals  dis- 
tally appear  single  small  isolated  plates  which  proximally  become 
larger  and  continuous,  forming  an  inconspicuous  column  of  radial 
ossicles.  On  each  side  of  this  column  are  inserted  a  number  of  appar- 
ently irregularly  arranged  small  accessory  plates  which  are  like  those 
of  the  disk.  All  of  the  plates  of  the  abactinal  area  are  finely  tuber- 
culose,  these  points  being  for  the  attachment  of  very  fine,  short  spines. 

Madreporite  small,  rounded,  not  very  convex,  very  finely  radially 
striated  and  resting  directly  upon  two  basal  supramarginal  plates  of 
adjoining  rays. 

Ocular  plates  small  but  distinct,  one  terminating  each  ray  and  rest- 
ing against  the  distal  marginal  plates. 

Supra-  and  inframarginal  plates  large  and  conspicuous,  apparently 
firmly  united  and  indistinguishable  laterally  as  separate  columns. 
Abactinally  the  supramarginal  plates  are  wider  and  overlie  more  or 
less  the  adambulacrals. 

Adambulacrals  smaller  than  the  inframarginals  but  otherwise 
resemble  the  latter. 

Ambulacral  grooves  narrow.  Ambulacra!  plates  alternating,  about 
as  numerous  as  the  adambulacrals,  1—  -shaped,  with  the  podial  open- 
ings between  adjoining  plates. 

All  other  actinal  characters  unknown, 

Genoholotype  and  only  Jcnown  species. — Palseaster  crawfordsvillensis 
Miller.  From  the  Keokuk  crinid  beds  near  Crawfordsville,  Indiana. 

Remarks. — Neopalseaster  retains  a  very  primitive  abactinal  plate 
structure  and  calls  to  mind  Hudsonaster,  Palseaster,  and  typical 
Mesopalseaster.  It  is  distinguished  from  these  early  Paleozoic  genera 
by  the  complete  consolidation  of  the  supra-  and  inframarginal  plates 
into  one  column,  and  the  presence  of  ocular  plates.  The  inter- 
brachial  area  is  unknown  in  Neopalseaster,  but  its  abactinal  structure 
seems  to  indicate  a  single  interbrachial  plate  in  each  area  bounded 
distally  by  two  basal  inframarginal  plates.  If  this  interpretation  is 
correct,  then  this  character  will  further  distinguish  Neopalseaster  from 
Hudsonaster  and  Palseaster. 


136  BULLETIN"   88,   UNITED   STATES   NATIONAL  MUSEUM. 

NEOPAL^EASTER  CRAWFORD SVILLENSIS  (Miller). 

Plate  13,  fig.  5;  plate  23,  fig.  4. 

Palseaster  crawfordsmllensis  MILLER,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  2, 
1880,  p.  256,  pi.  15,  fig.  3;  N.  Amer.  Geol.  Pal.,  1889,  p.  265,  fig.  379. 

Original  description. — "This  species  is  founded  upon  the  dorsal 
view  of  a  single  specimen.  The  rays  are  longer  than  the  diameter  of 
the  body,  and  not  of  uniform  size.  They  are  flattened  or  depressed 
in  the  middle,  as  is  also  the  central  part  of  the  body.  Many  of  the 
plates  possess  a  central  tubercle  or  small  spine,  and  probably  all  of 
them  did. 

"The  marginal  plates  are  large;  somewhat  elliptical  in  outline,  and 
have  their  shorter  diameters  in  the  direction  of  the  length  of  the 
rays.  There  are  about  12  plates  on  each  side  of  a  ray,  and  they 
come  together  at  about  the  eighth  plate  from  the  body,  though  in 
the  ray  opposite  the  madreporiform  tubercle  they  come  together  at 
the  seventh.  The  space  between  the  marginal  plates  of  each  ray 
is  filled  with  smaller  plates;  three  of  these  unite  the  larger  plates  at 
the  body,  but  they  diminish  in  number  toward  the  apex  of  the  ray, 
and  cease  at  the  eighth  plate.  In  addition  to  the  two  large  plates 
which  form  the  junction  of  the  rays  with  the  body,  a  few  large  plates 
cover  the  outer  part  while  the  central  part  is  covered  by  smaller 
plates.  The  madreporiform  tubercle  is  supported  by  three  plates, 
two  of  them  are  large  marginal  plates,  which  form  a  junction  between 
two  rays,  and  the  other  is  a  large  plate  within,  forming  part  of  the 
covering  of  the  body." 

Emended  description. — The  type-specimen  measures:  R,  =  22  mm., 
r=7  mm.,  K,  =  3.1r>.  Width  of  rays  at  base  7  mm.  Another  speci- 
men in  the  Museum  of  Comparative  Zoology  has  rays  3  mm.  longer. 

Rays  short,  tapering  rapidly.     Disk  rather  large  for  a  small  species. 

Abactinally  the  disk  has  a  central  circular  plate  surrounded  by 
numerous  small,  conical,  irregularly  disposed,  accessory  plates,  among 
which  are  a  few  larger  pieces  usually  adjacent  to  the  large  interradial 
plates.  Outside  of  the  small  disk  plates  is  a  ring  of  very  large,  irregu- 
larly shaped,  radial  and  interradial  plates.  Five  of  these  are  inter- 
radial  in  position,  and  are  situated  just  within  the  basal  plates  of 
adjoining  supramarginal  columns.  These  plates  may  remain  normal 
as  a  single  plate  or  may  be  divided  into  two  plates,  when  they  some- 
what resemble  inwardly  crowded  supramarginals.  Upon  these 
laterally  and  distally  rest  five  large  radial  pieces,  the  basal  plates 
of  the  radial  columns.  It  is  very  probable  that  the  radial  columns 
are  continuous  from  the  basal  plate  to  near  the  distal  portion  of  the 
ray,  where  a  few  of  these  plates  are  much  reduced  in  size  and  are 


EEVISIOIST   OF   PALEOZOIC   STELLEEOIDEA.  137 

separated  and  wedged  in  between  the  adjoining  four  supramarginal 
ossicles.  There  appear  to  be  10  or  11  of  these  in  a  column.  On  each 
side  of  the  radial  columns  in  the  proximal  half  of  each  ray  are  a  number 
of  small  accessory  plates  arranged  in  irregular  columns.  All  of  the 
abactinal  plates  are  more  or  less  convex  and  bear  numerous  small 
pustules  clustered  around  a  larger  central  one,  all  of  which  bore  small 
spines. 

Supramarginal  plates  very  conspicuous,  subquadr angular  in  out- 
line, generally  a  little  wider  than  long,  with  numerous  small  pustules, 
among  which  toward  each  lateral  edge  is  a  large  one  upon  which 
probably  articulated  prominent  spines.  There  are  from  11  to  13  of 
these  plates  in  each  column.  In  the  distal  third  of  a  ray  both 
columns  approximate  and  adjoin  each  other  closely.  Each  supra- 
marginal  plate  lies  wholly  and  directly  over  an  inframarginal  and  the 
pieces  appear  as  one  consolidated  plate  with  the  abactinal  side  convex 
and  the  actinal  nearly  flat.  The  supramarginals  are  the  widest  and 
extend  in  part  over  the  adambulacrals. 

Madreporite  small,  circular  in  outline,  slightly  convex  and  very 
finely  radially  striated.  It  lies  directly  upon  two  basal  supramar- 
ginal plates  of  adjoining  rays  and  directly  outside  of  one  of  the  large 
interradial  plates. 

An  ocular  plate  terminates  each  ray. 

Inframarginals  apparently  like  the  supramarginals  excepting 
distally,  where  they  are  nearly  twice  as  long  as  wide. 

Adambulacral  plates  smaller  than  the  inframarginals,  nine  in 
the  space  occupied  by  five  of  the  latter,  somewhat  wider  than  long, 
convex,  and  covered  with  numerous  small  pustules. 

Ambulacral  grooves  very  narrow  in  the  distal  region.  The  ambu- 
lacral  plates  appear  to  be  as  numerous  as  the  adambulacrals,  and  are 
h-  -shaped,  with  the  podial  openings  between  the  plates  in  about  the 
mid-width  of  the  column. 

All  other  actinal  characters  are  unknown,  since  the  two  specimens 
expose  the  abactinal  area,  though  one  has  portions  of  the  plates 
removed,  revealing  the  actinal  characters  described. 

Formation  and  locality. — The  type-specimen  is  in  the  Harris 
collection  of  the  United  States  National  Museum,  and  another 
specimen  is  in  the  Dyer  collection  of  the  Museum  of  Comparative 
Zoology  (No.  4).  Both  were  found  in  the  crinid  beds  of  the  Keokuk 
group  of  the  Lower  Carboniferous  at  Crawfordsyille,  Indiana. 

Remarks. — There  is  no  Carboniferous  asterid  with  which  Neopalse- 
aster  crawfordsvillensis  can  be  confounded. 

Cat.  No.  60607,  U.S.N.M. 


138  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

Family  PALASTERINID^E  Gregory  (emend.). 

Pateasterinidse  GREGORY  (part),  Geol.  Mag.,  dec.  4,  vol.  6,  1899,  p.  348  (contains 
Palasterina,  Schaenaster,  and  Schuchertia)}  Treat.  Zool.,  vol.  3,  Echinoderma, 
1900,  p.  250. 

Lindstromasterinss  GREGORY  (part),  Geol.  Mag.,  dec.  4,  vol.  6, 1899,  p.  346  (contains 
Lindstromaster  and  Uranaster). 

Palseasterinidse  STURTZ,  Palaeontographica,  vol.  36,  1890,  p.  246. 

Progressive  Phanerozonia  developing  large  interbrachial  arcs. 
Ambulacral  plates  more  or  less  alternate.  Madreporite  abactinal. 
Disk  large,  pentagonal,  and  the  rays  separated  by  well-developed 
interbrachial  arcs.  The  inframarginal  plates  bound  the  animal  and 
are  separated  from  the  adambulacrals  more  or  less  completely  by  a 
varying  number  of  interbrachial  plates. 

Abactinal  surface  with  longitudinal  columns  of  radial,  supra- 
marginal  and  accessory  columns  of  plates,  or  the  radial  columns 
may  be  reduced  or  even  replaced  by  transverse  rows  of  small  accessory 
pieces.  The  central  region  of  the  disk  may  retain  a  ring  of  larger 
basal  radial  and  supramarginal  pieces. 
Contains: 

Pet  raster  Billings. 

Lindstromaster  Gregory. 

Palasterina  McCoy. 

Uranaster  Gregory. 

Palxostella  Stiirtz. 

Pseudopalasterina  Stiirtz. 

Genus  PETRASTER  Billings. 

Plates  23,  26,  27. 

Petraster  BILLINGS,  Geol.  Surv.  Canada,  Can.  Org.  Rem.,  dec.  3,  1858,  p.  79. — 
HALL,  Twentieth  Rep.  N.  Y.  State  Cab.. Nat.  Hist.,  1868,  pp.  283,  294;  rev. 
ed.,  1868=1870,  pp.  325,  337. 

Palseaster  (part)  ZITTEL,  Handb.  Pal.,  vol.  1,  1879,  p.  452. 

PalsRosterina  of  some  AUTHORS. 

Generic  characters. — Disk  and  interbrachial  arches  more  or  less 
large.  General  shape  pentagonal.  Rays  five,  short  and  slender  or 
stout  and  tapering  rapidly. 

Abactinal  area  of  rays  distally  with  one  medial  radial,  two  supra- 
marginal  and  two  inframarginal  columns  of  plates.  Between  the 
radial  and  supramarginal  columns  proximally  are  inserted  columns 
of  accessory  plates'  In  P.  speciosus  there  are  five  on  each  side  of 
the  radial  column.  Between  the  supramarginal  and  iinVaniarginal 
columns  in  the  axillary  and  basal  ray  regions  are  inserted  columns 
of  ambital  plates.  In  P.  speciosus  there  are  three.  The  plates 
are  more  or  less  stellate,  with  numerous  subcircular  openings  in  the 
angles  between  adjoining  plates. 


REVISION    OF   PALEOZOIC    STELLEKOIDEA.  139 

Inframarginal  plates  bounding  the  entire  outer  edge  of  the  animal, 
conspicuous,  closely  adjoining,  not  stellate  and  common  to  both  the 
actinal  and  abactinal  areas. 

Madreporite  radially  striate,  abactinal. 

Adambulacrals  closely  adjoining  the  inframarginals  in  the  distal 
portion  of  the  rays  but  proximally  the  former  are  separated  from  the 
latter  by  more  or  less  numerous,  small,  accessory  interbrachial  plates. ' 
The  adambulacrals  may  be  of  nearly  the  same  size,  or  considerably 
wider  than  long  in  the  mid-length  of  the  column.  The  adambula- 
crals of  adjoining  columns  meet  orally  in  a  pair  of  larger  triangular 
plates,  the  oral  armature. 

Interbrachial  areas  more  or  less  large  and  the  space  between  the 
inframarginal  and  adambulacral  columns  filled  with  a  variable 
number  of  accessory  interbrachial  plates. 

Ambulacrals  slightly  alternating,  about  as  numerous  as  the  adam- 
bulacrals, each  with  an  L-shaped,  proximally  converging  carina. 
Podial  openings  through  the  outer  proximal  corner  of  the  plate  and 
proximal  to  the  carina.  Grooves  narrow,  regularly  tapering. 

GenoJiolotype  (type  by  monotypy). — Petraster  rigidus  Billings.  The 
above  diagnosis  is  based  on  the  genotype  and  Pal&asterina  spedosa 
Miller  and  Dyer. 

Distribution. — Ordovicic  of  North  America,  Siluric  of  Australia. 

The  species  are: 

P.  rigidus  (Billings).     Trenton. 

P.  speciosus  (Miller  and  Dyer).     Maysville,  Kichmond. 

P.  (?)  americanus  (D'Orbigny).     Maysville. 

P.  smythi  McCoy.     Siluric  of  Australia. 

'Remarks. — While  Billings  has  correctly  pointed  out  the  diagnostic 
characters  of  Petraster,  yet  the  genus  has  been  very  imperfectly 
understood.  This  may  partly  be  accounted  for  in  that  he  later  also 
included  a  specimen  of  Hudsonaster  matutinus  (Hall),  which  of  course 
fails  to  have'  the  essential  generic  character  of  Petraster,  namely,  the 
interbrachial  accessory  plates.  The  following  is  Billings'  original 
description: 

"This  genus  has  both  marginal  and  adambulacral  plates,  with  a 
few  disk-plates  on  the  ventral  side.  The  general  form  is  deeply 
stellate,  and  the  rays  long  and  uniformly  tapering.  A  single  specimen 
has  been  collected,  and  as  it  shows  the  underside  only,  the  characters 
of  the  dorsal  surface  can  not  be  given.  The  structure  of  the  mouth 
is  also  unknown.  Generic  name  from  petra,  a  stone. 

"It  differs  from  Palasterina  by  the  presence  of  large  marginal 
plates  outside  of  the  disk-plates  [that  genus  has  small  marginals], 
and  still  more  from  Stenaster,  which  has  neither  disk  nor  marginal 
plates.  It  is  allied  to  Astropecten." 


140  BULLETIN   88,  UNITED   STATES   NATIONAL   MUSEUM. 

Professor  Hall  at  first  recognized  the  distinctness  of  Petraster,  since 
he  wrote  as  follows  (1870): 

"The  character  of  Petrasier  here  described,  and  illustrated  in  the 
figure  (3a,  pi.  9),  gives  an  intercalated  partial  range  of  disk-plates, 
between  the  adambulacral  and  marginal  plates,  which  will  separate 
these  forms  from  any  of  the  Palaeasters  in  my  collection.'7 

On  a  later  page,  after  an  examination  of  the  genotype,  he  added 
a  "Note  on  the  genus  Petraster"  in  which  he  concludes  that  the 
specimen  was  injured  during  life,  as  shown  by  the  unequal  distribu- 
tion of  the  accessory  interbrachial  plates,  and  further  that  one  ray 
is  "without  intercalated  plates  on  either  side.'7  He  adds:  "This 
yiew  is  sustained  by  the  fact  that  the  other  parts  have  the  ordinary 
structure  of  Palseaster,  and  in  all  other  respects  the  specimen  agrees 
with  the  typical  Palseaster  matutina."  The  genotype  was  studied 
at  Ottawa  by  the  present  writer  and  found  to  be  as  described  by 
Billings.  The  accessory  interbrachial  plates,  though  somewhat 
irregular  in  development  in  different  areas  in  the  type  species  of 
Petraster,  are  normal  in  position  and  a  similar  but  more  complete 
development  also  appears  in  Lindstromaster  and  Palasterina. 

Petraster  is  distinguished  from  Palasterina  as  follows:  The  most 
important  feature  is  that  the  inframarginal  plates  of  the  former 
are  prominent,  closely  adjoining  and  short  but  wide,  while  in  Palas- 
terina they  are  small,  not  conspicuous,  and  globular,  or  subquadrate. 
The  next  important  difference  is  on  the  abactinal  disk,  where  in 
Palasterina  there  is  an  irregular  ring  of  prominent  basal  radial, 
and  supramarginal  plates.  These  are  absent  in  Petraster.  The  acces- 
sory interbrachial  ossicles  in  the  latter  genus  never  attain  the  distal 
region  of  the  rays  as  in  Palasterina  where  these  pieces  are  also  more 
numerous.  Palasterina  is  also  more  abundantly  spinose  than 
Petraster. 

Schuchertia  has  no  inframarginals  as  marginal  plates,  which  at 
once  distinguishes  it  from  both  Petraster  and  Palasterina.  It  is 
true  that  in  Schuchertia  inframarginals  are  also  present  but  they  are 
usually  not  well  developed  and  remain  adjoining  the  adambulacrals. 
These  two  columns  are  therefore  not  separated  from  one  another  by 
accessory  interbrachial  plates  as  in  Petraster  and  Palasterina. 

The  primary  structure  of  Petraster  is  that  of  Hudsonaster.  So  many 
of  the  generic  characters  are  common  to  both  that  the  former  genus 
appears  almost  certainly  to  have  been  derived  through  the  latter. 
It  is  true  that  the  central  abactinal  area  of  the  disk  in  Petraster  is 
devoid  of  the  large  basal  plates,  a  marked  character  in  Hudsonaster, 
but  the  other  generic  characters  are  all  present  in  the  former.  Petras- 
ter adds  more  or  less  numerous  columns  of  radial  accessory  ambital 
and  accessory  interbrachial  plates,  none  of  which  are  present  in 
Hudsonaster.  It  is  these  accessory  ossicles  which  differentiate  these 


OF  PALEOZOIC  STELLEKOIDEA.  141 

genera  and  show  the  line  of  development  from  the  deeply  stellate 
primary  form  to  the  pentagonal  genera  with  well-developed  inter- 
brachial  arcs. 

PETRASTER  RIGIDUS  (Billings). 
Plate  27,  fig.  5. 

Palasterina  rigidus  BILLINGS,  Geol.  Surv.  Canada,  Rep.  of  Progress,  1853-1856, 

1857,  p.  291. 
Petraster  rigidus  BILLINGS,  Geol.  Surv.  Canada,  Can.  Org.  Hem.,  dec.  3,  1858, 

p.  80,  pi.  10,  fig.  3a  (not  fig.  3b—Hudsonaster  matutinus} . — WRIGHT,  Mon. 

British  Foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1  (Palaeontogr.  Soc.  for  1861), 

1862,  p.  29.— HALL,  Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  1868,  p. 

294;  rev.  ed.,  1868=1870,"  p.  337. 

Description  of  1858. — "This  species  has  much  the  aspect  of  an 
Astropecten;  the  disk  is  one-fourth  the  whole  diameter,  the  rays 
rather  slender  and  uniformly  tapering,  the  angles  between  the  bases 
of  the  rays  rounded.  The  plates  [of  the  actlnal  side]  which  appear  to 
be  adambulacral  [increase  very  little  in  size  from  the  tips  of  the  rays 
toward  the  mouth],  are  quadrate  and  a  little  convex;  [the  adambula- 
cral columns  terminated  in  the  mouth  area  by  a  pair  of  pointed 
oral  plates  and  not  by  a  single  plate  as  shown  in  the  original  illustra- 
tion], the  marginal  [inframarginal]  plates  oblong,  and  also  convex 
[certainly  not  less  than  16  and  probably  20  in  each  column,  increasing 
rapidly  in  size  toward  the  axils,  whsre  there  is  a  single  large  axillary 
plate] ;  the  disk  plates  [accessory  interbrachials]  consist  of  three  at 
each  angle  [one  orally  and  two  distally],  and  a  single  row  [of  not  more 
than  seven  plates]  on  each  side  of  the  ray,  but  extending  only  one- 
third  or  one-half  of  the  length  of  the  ray;  they  all  lie  between  the 
[infra]  marginal  and  adambulacral  plates.  [Abactinal  side  unknown.] 
The  specimen  figured  was  about  2  inches  [or  50  mm.-]  in  diameter 
when  perfect ;  width  of  disk  half  an  inch,  and  of  rays  at  the  base  about 
three  lines." 

Formation  and  locality. — Trenton  limestone,  Ottawa,  Canada. 
Holotype  No.  140 la  is  in  the  Victoria  Memorial  Museum,  Ottawa. 
The  species  has  also  been  identified  by  Springer  in  the  Lower  Trenton 
(Kirkfield)  at  Kirkfield,  Ontario. 

Remarks. — Hall  and  Billings  discussed  their  asterid  genera  and 
species  at  different  times  and  finally  the  former  examined  Billings' s 
material.  In  this  connection  Hall  showed  that  figure  3&  of  Petraster 
rigidus  was  based  on  the  actinal  side  of  Hudsonaster  matutinus. 
Regarding  figure  3a,  which  is  the  holotype  of  this  species,  he  in  1870 
wrote  as  follows: 

"The  specimen  illustrated  in  figure  3a  has  a  few  small  intercalated 
plates  between  the  marginal  and  ambulacral  [adambulacral]  ranges 
in  two  of  the  axils  of  the  rays,  and  there  are  a  smaller  number  of  gran- 
ules in  a  similar  position  but  unequally  distributed  on  one  side  of 


142  BULLETIN   88,  UNITED  STATES  NATIONAL  MUSEUM. 

another  axil,  while  two  of  the  axils  do  not  show  any  such  intercalated 
plates  or  granules.  In  one  of  the  rays,  at  least,  the  ambulacral,  adam- 
bulacral,  and  marginal  plates  are  distinctly  visible,  without  inter- 
calated plates  on  either  side. 

"The  presence  of  these  unequally  distributed  plates  or  granules 
is  apparently  an  abnormal  structure,  probably  the  result  of  accident 
during  the  growth  of  the  animal;  and  this  view  is  sustained  by  the 
fact  that  the  other  parts  have  the  ordinary  structure  of  Palseaster, 
and  in  all  other  respects  the  specimen  agrees  with  the  typical  Palse- 
aster matutina" 

The  holotype  was  examined  by  the  writer  and  although  imperfect 
was  found  to  have  a  normal  development,  with  the  plates  in  their 
proper  places  in  at  least  two  of  the  rays  and  axils.  It  certainly  is  not 
an  abnormal  development  of  "Palseaster  matutina"  but  represents 
a  normal  individual  of  a  distinct  genus  and  species  diverging  from 
Eudsonaster  matutinus  toward  the  forms  with  large  disks  and  great 
axillary  areas,  as  in  Lindstromaster  and  Palasterina.  Hall  seemingly 
was  led  to  make  the  erroneous  remarks  above  quoted  through  the 
fact  that  Billings  had  also  included  in  his  description  a'nd  illustration 
(36)  an  individual  of  Hudsonaster  matutinus,  an  error  due  to  the 
undoubtedly  close  relationship  of  this  form  with  Petraster  rigidus. 

PETRASTER  SPECIOSUS  (Miller  and  Dyer). 

Plate  23,  figs.  5-7;  plate  26,  fig.  1;  plate  27,  figs.  1-4. 

Palssasterina  spedosa  MILLER  and  DYER,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  1, 
1878,  p.  30,  pi.  1,  fig.  7.— MILLER,  N.  Amer.  Geol.  Pal.,  1889,  p.  266,  fig.  381. 

Paldeasterina  approximata  MILLER  and  DYER,  Journ.  Cincinnati  Soc.  Nat.  Hist., 
vol.  1,  1878,  p.  30,  pi.  1,  fig.  8. 

Original  description  of  Palseasterina  spedosa. — "Pentagonal;  rays 
obtuse  at  their  apices;  greatest  distance  from  point  to  point  about 
2J  inches;  breadth  of  body  between  rays  about  1J  inches,  and  dis- 
tance from  tip  of  ray  to  next  adjoining  tip  on  either  side  about  1J 
inches. 

"The  [infra]  marginal  plates  are  small  and  somewhat  hemispher- 
ical near  the  termination  of  the  rays,  they  gradually  enlarge  and 
become  square,  and  then  rectangular  as  they  approach  the  disk,  until 
at  the  narrowest  part  of  the  disk  or  body  of  the  fossil  they  are  twice 
as  long  as  wide.  There  are  about  50  marginal  plates  between  the 
apex  of  one  ray  and  the  next  one  adjoining,  or,  in  a  perfect  specimen 
of  this  size,  about  250. 

"The  back  or  dorsal  side  is  covered  with  numerous  plates  (prob- 
ably in  a  complete  specimen  of  this  size  there  would  be  1,000  or  more), 
which  are  very  prominent  in  the  center  or  somewhat  conical,  and 
seem  to  have  been  joined  together  with  deeply  serrated  edges. 
The  plates  have  from  three  to  eight  of  these  indentations,,  which 
give  them  a  beautiful  starlike  appearance. 


KE VISION"    OF   PALEOZOIC    STELLEROIDEA.  143 

"The  ambulacral  grooves  are  narrow  and  deep,  as  shown  by  the 
sharp  ridges  on  the  back  of  the  specimen.  The  small  dorsal  plates 
which  cover  the  ambulacral  pieces  are  exfoliated  in  some  places, 
and  show  two  rows  of  ambulacral  plates  coming  evenly  together 
and  forming  the  sharp  ridge.'' 

Original  description  of  Palseasterina  approximate, . — " Pentagonal; 
rays  more  slender  than  in  P.  speciosa;  greatest  distance  from  point 
to  point  in  the  specimen  figured  1.15  inches  and  breadth  of  the 
body  one-half  inch;  another  specimen  from  the  collection  of  Mrs. 
M.  P.  Haines,  of  Richmond,  Ind.,  measures  from  point  to  point  2.5 
inches,  and  has  a  breadth  of  body  of  nine-tenths  inch. 

"The  [infra]  marginal  plates  have  about  the  same  form,  and  are 
about  as  numerous  as  they  are  in  P.  speciosa.  The  adambulacral 
plates  are  arranged  with  their  length  across  the  rays.  The  oral 
plates  are  very  prominent.  [This  statement  is  somewhat  in  error. 
The  five  prominent  points  around  the  mouth  are  each  formed  of  one 
large  interbrachial  plate  and  a  pair  of  proximal  adambulacrals.]  The 
space  between  the  [infra]  marginal  plates  and  the  oral  ones  [adambu- 
lacrals] is  filled  with  numerous  small  [accessory  interbrachial]  pieces. 
The  ambulacral  grooves  are  narrow.  Ambulacral  ossicles  unknown. 

"The  dorsal  side  is  covered  with  small  conical  pieces,  which  give 
it  a  coarsely  granular  appearance.  The  madreporiform  tubercle 
is  prominent,  conical,  and  longitudinally  striated. 

"This  species  is  distinguished  from  P.  speciosa  by  its  narrower 
rays,  more  contracted  body,  and  smaller  dorsal  plates." 

Emended  description. — The  holotypo  of  P.  speciosa  measures: 
R  =  33  mm.,  r  —  18  mm.  The  holotype  of  P.  approximata  measures: 
R  =  15  mm.,  r  =  6.5  mm. 

Rays  in  young  specimens  slender  distally,  but  with  age  they 
become  obtuse  and  very  wide  proximally  and  here  merge  into  the  large 
disk.  Interbrachial  arcs  very  large. 

The  abactinal  area  of  disk  and  rays  is  bounded  by  columns  of  very 
prominent  inframarginal  plates.  Beginning  at  the  apex  of  each  ray 
they  are  very  small  and  globular,  soon  they  become  quadrate  and 
gradually  shorter  but  wider,  so  that  near  the  middle  of  each  interbra- 
chial arc  they  have  a  crowded  appearance.  In  a  full-grown  specimen 
there  are  about  50  and  hi  a  half-grown  example  about  45  of  these 
plates  between  the  distal  ends  of  adjoining  rays.  In  the  distal  region 
these  plates  are  rounded  and  nearly  smooth  but  gradually  become 
granular  and  strongly  convex,  each  with  one  prominent  point  for  an 
articulating  spine,  none  of  which,  however,  have  been  observed.  On 
the  actinal  side  these  inframarginals  are  also  very  prominent  and 
pustulose  but  here  are  flat.  They  are  most  prominent  near  the  center 
of  the  interbrachial  arcs. 

50601°— Bull.  88 — 15 10 


144  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

The  supramarginal  columns  begin  at  the  very  apex  of  the  rays 
and  for  more  than  one- third  of  their  length  adjoin  the  inframarginals 
where  ambital  plates  begin  to  appear.  The  supramarginal  columns 
are  continuous  over  the  disk  in  a  broad  curve,  with  about  18  to  20 
in  a  column,  or  from  apex  to  apex  of  adjoining  rays  there  are  from 
35  to  40  of  these  plates.  In  the  axillary  areas  they  are  separated 
from  the  inframarginals  by  three  or  four  rows  of  ambital  plates.  At 
the  apex  of  the  rays  the  supramarginals  are  highly  convex  and 
nearly  circular  in  outline  but  soon  pass  into  more  and  more  dis- 
tinctly stellate  plates.  This  is  the  form  of  all  the  abactinal  plates 
inside  of  the  inframarginals ;  they  are  stellate,  highly  convex,  each 
with  a  central  node  for  an  articulating  spine  and  a  few  granules 
that  are  the  bases  for  smaller  spines. 

Each  radial  column  appears  immediately  beneath  the  two  terminal 
or  rather  distal  supramarginal  plates  and  then  continues  as  a  column 
to  near  the  center  of  the  disk.  They  are  more  prominent  than  the 
other  columns  excepting  the  marginals  and  have  not  less  than  25 
plates  in  each  one.  On  each  side  of  the  radials  are  five  columns  of 
radial  accessory  plates  which  appear  to  continue  as  columns  over  the 
disk  in  broad  curves  joining  those  of  the  next  ray.  Between  these 
columns  in  the  axillary  areas  are  additional  accessory  plates.  These 
columns  of  accessory  plates  appear  singly,  first  on  one  side  and  later 
on  the  other,  and  not  in  pairs  simultaneously,  one  on  each  side  of  the 
radial  columns. 

Ambital  areas  well  developed  in  the  axillary  region,  where  there 
are  about  three  columns  of  these  plates.  The  columns  pinch  out 
rapidly  dis tally  and  none  are  present  in  the  outer  third  of  the  rays. 

The  plate  arrangement  of  the  central  part  of  the  disk  can  not  be 
made  out. 

Madreporite  of  medium  size,  highly  conical,  and  conspicuous, 
with  numerous  sharp  single  or  bifurcating  ridges;  on  the  under  side 
are  seen  two  outwardly  directed  spiral  cones  (the  white  lines  of  the 
drawing  representing  the  spiral  tubes  in  the  madreporite),  reminding 
one  of  the  brachia  in  Atrypa  (pi.  27,  fig.  4). 

Adambulacral  plates  depressed,  convex,  subquadrangular  in  out- 
line in  young  specimens,  but  in  fully  grown  individuals  a  number  of 
these  in  the  central  region  of  the  column  are  much  drawn  out  laterally 
and  are  here  two  or  three  times  as  wide  as  long.  In  a  half-grown 
individual  there  are  about  20  of  these  plates  in  a  column,  but  in  a 
mature  specimen  there  appear  to  be  not  less  than  26.  These  plates 
end  inwardly  in  an  apex,  against  which  terminate  the  ridges  of  the 
ambulacral  plates.  The  adambulacral  and  inframarginal  columns 
are  closely  adjoining  in  the  distal  two-thirds  of  the  rays  but  proxi- 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  145 

mally  they  are  separated  from  each  other  by  numerous  accessory 
interbrachial  plates,  of  which  there  appear  to  be  not  less  than  30  in 
each  area.  The  apexes  of  these  interbrachial  areas  form  the  oral 
armature  and  each  consists  of  two  adambulacral  plates,  back  of 
which  is  a  rather  large  interbrachial  plate. 

Ambulacra!  grooves  narrow,  tapering,  and  deeply  V-shaped. 
Ambulacral  plates  slightly  alternating,  about  as  long  as  wide,  and 
proximally  superposed,  with  about  26  in  each  column.  Each  plate 
has  an  L-shaped  ridge  with  the  point  proximally  directed.  The 
podial  openings  are  situated  in  the  outer  proximal  corner  of  the 
plates  and  between  the  inner  angles  of  two  adambulacrals. 

Formation  and  locality. — Richmond  and  Maysville  formations  of 
the  Upper  Ordovicic.  The  holotype  of  P.  speciosa  was  found  by 
Mr.  W.  C.  Barnhart,  on  Twin  Creek,  near  Winchester,  in  Preble 
County,  Ohio,  and  is  now  in  the  Dyer  collection  of  the  Museum  of 
Comparative  Zoology,  Harvard  University  (No.  14).  Four  other 
less  well-preserved  specimens  are  in  the  Harris  collection  of  the 
United  States  National  Museum  and  were  found  in  the  vicinity  of 
Waynesville,  Ohio.  The  holotype  of  P.  approximata  and  another 
similar-sized  specimen  but  not  so  well  preserved  are  also  from  the 
vicinity  of  Waynesville,  Ohio.  The  first  is  in  the  Dyer  collection 
of  the  Museum  of  Comparative  Zoology  (No.  15),  and  the  other  in 
the  United  States  National  Museum.  There  is  a  slab  with  two 
young  individuals  much  etched  with  acid  but  otherwise  excellent, 
showing  the  actinal  side,  in  the  Gurley  collection  of  the  University 
of  Chicago  (No.  10979).  Finally  there  are  two  fine  specimens,  not 
fully  grown,  showing  well  the  actinal  and  abactinal  sides,  in  the 
Haines  collection  of  the  same  university  (Nos.  10839  and  10840), 
found  near  Hamilton,  Ohio;  these  are  apparently  from  the  very  top 
of  the  Maysville  formation. 

Remarks. — P.  speciosa  is  described  by  Miller  and  Dyer  from  the 
abactinal  side  and  P.  approximata  from  the  actinal  side.  These 
writers  point  out  that  the  rays  are  more  slender  and  the  disk  more 
contracted  in  the  latter,  but  when  one  considers  that  it  is  less  than 
half  the  size  of  the  former  and  that  during  growth  these  forms  con- 
tinually add  accessory  plates,  this  difference  hi  form  is  seen  to  be 
one  of  growth.  The  '  'smaller  dorsal  plates"  noted  by  these  writers  in 
Mrs.  Haines's  specimen  of  P.  approximata  are  a  character  which  the 
present  writer  does  not  regard  as  of  value  unless  they  be  constant 
at  this  lower  geologic  horizon  (Maysville  at  Hamilton),  in  which  event 
this  specimen  can  later  on  be  distinguished  by  another  specific  name. 

Cat.  No.  60609,  U.S.N.M. 


146  BULLETIN    88,   UNITED    STATES   NATIONAL   MUSEUM. 

PETRASTER  (?)  AMERICANTJS  (D'Orbigny). 
Plate  26,  fig.  2. 

Asterias  GRAHAM,  ANTHONY,  and  JAMES,  Amer.  Journ.  Sci.,  eer.  2,  vol.  1,  1846, 

p.  441,  figure  but  no  description. 
Ccelaster  americanus  D'ORBIGNY,  Prodr.  de  Paleont.,  vol.  1,  1849,  p.  22  (name 

proposed). 
Asterias  anikonii  DANA,  Manual  Geol.,  ed.  1,  1863,  p.  221,  with  figure  but  no 

description. 
Palasterina  (tyjamesi  DANA,  Amer.  Journ.  Sci.,  ser.  2,  vol.  35, 1863,  p.  295;  Manual 

Geol.,  ed.  2,  1864,  p.  221,  with  figure  but  no  description. 
Palseaster  jamesi  HALL,  Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  1868,  p.  286; 

rev.  ed.,  1868=1870,  p.  329.— MEEK,  Geol.  Surv.  Ohio,  Pal.,  vol.  1,  1873, 

p.  62,  pi.  4,  fig.  4. 

Meek's  description. — "  Through  the  kindness  of  Mr.  U.  P.  James, 
of  Cincinnati,  the  discoverer  of  this  fossil,  I  have  now  before  me  the 
original  typical  specimen,  which  I  found  not  in  a  condition  to  be 
fully  and  systematically  characterized,  nor  perhaps  to  afford  the 
means  of  determining,  beyond  doubt,  its  generic  affinities.  It 
evidently  attained  a  large  size,  and  has  a  comparatively  large  disk, 
with  its  five  rays  rather  broad  at  their  inner  ends,  somewhat  rapidly 
tapering,  and  apparently  longer  than  the  diameter  of  the  disk.  It 
evidently  lies  [does  lie]  in  the  matrix  in  such  a  manner  as  to  show  the 
ventral  side  [the  inner  dorsal  aspect  of  the  ventral  plates],  but  pre- 
sents the  appearance  of  having  the  marginal  and  disk  plates  of  this 
side  removed  [they  are  present].  The  five  pairs  of  oral  pieces  [proxi- 
mal adambulacral  plates]  are  seen  in  place,  and  proceeding  outward 
from  these  can  be  seen  a  row  of  adambulacral  pieces  on  each  side 
of  each  of  the  rather  wide  [narrow]  ambulacral  furrows.  These 
latter  pieces  are  [proximally]  nearly  three  times  as  long  as  their 
diameters  in  the  direction  of  the  length  of  the  rays,  and  quite  promi- 
nent at  their  inner  ends,  where  they  are  articulated  together  by  little 
processes  and  corresponding  sockets  or  sinuses;  while  the  outer 
two-thirds  of  each  is  flattened  and  distinctly  more  depressed  than 
their  inner  ends.  Outside  of,  and  alternating  with,  the  outer  flat- 
tened ends  of  these  adambulacral  pieces,  a  row  of  [inframarginal] 
nearly  square,  or  more  or  less  oblong  pieces,  may  be  seen  all  along  the 
margins  of  the  rays,  and  connecting  at  their  axilla  in  such  a  manner 
as  to  leave  room  for  several  disk  [or  interbrachial]  plates  between 
them  and  the  oral  and  inner  adambulacral  pieces." 

In  each  interbrachial  area  there  are  inserted  between  the  infra- 
marginals  and  adambulacrals  interbrachial  plates  as  follows:  Proxi- 
mally one  hexagonal  plate  upon  which  rest  two  similar  plates  mar- 
gined by  the  inframarginals. 

"At  some  places  within  the  [narrow]  ambulacral  furrows,  remains 
of  ambulacral  ossicula  can  be  seen  deeply  interlocking  with  the 
inner  ends  of  the  adambulacral  pieces,  but  their  exact  form,  and  the 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  147 

position  and  arrangement  of  the  ambulacra!  pores,  can  not  be 
clearly  made  out  in  the  specimen  studied. 

"The  two  oral  pieces  [proximal  adambulacrals]  of  each  of  the 
five  pairs  are  separated  by  deep  sutures,  and  have  an  irregular  form, 
being  longer  than  wide,  and,  like  the  adambulacral  pieces,  which 
they  somewhat  exceed  in  size,  flattened  and  depressed  at  their  outer 
ends,  and  elevated  into  crestlike  prominences  farther  in,  with  a 
lateral  process  or  thickening  on  the  outer  side  of  each,  in  which  a  more 
or  less  distinct  pit  may  be  seen."  Between  the  pairs  of  oral  adam- 
bulacral plates  are  inserted  small,  single,  sub  quadrangular  plates, 
the  proximal  plate  of  each  pair  of  ambulacral  ossicles.  Orad  to 
each  pair  of  oral  armature  plates  are  situated  single  hemispheric 
plates. 

"The  surface,  and  the  arrangement  of  the  dorsal  parts,  are  un- 
known; but  they  were  probably  armed  with  short  spines,  as  some 
remains  of  little  spines  are  seen  in  the  matrix  at  the  margin  of  the 
disk,  at  one  place. 

"As  the  extremities  of  none  of  the  rays  can  "be  clearly  seen,  the 
exact  breadth  of  the  whole  fossil,  between  the  ends  of  opposite 
rays,  can  not  be  exactly  given,  but  it  is  evident  that  the  length  of 
one  of  the  rays,  measuring  from  the  middle  of  the  disk,  must  have 
been  a  little  more  than  2  inches,  and  consequently  that  the  diam- 
eter across  from  the  extremities  of  opposite  rays  could  not  be  less 
than  about  4  inches.  The  breadth  of  the  disk  is  1.20  inches; 
and  that  of  the  rays  at  their  inner  ends,  0.70  inch." 

Formation  and  locality. — The  single  specimen  was  found  in  the 
Maysville  formation  (Ordovicic),  by  Mr.  U.  P.  James,  on  or  near 
Vine  Street  hill,  Cincinnati,  Ohio,  and  is  now  in  the  James  collection 
of  the  Walker  Museum  of  the  University  of  Chicago. 

Remarks. — This  large  species  is  quite  distinct  from  any  other  star- 
fish in  having  three  rows  of  interbrachial  plates,  one  piece  in  the  proxi- 
mal, two  in  the  medial,  and  five  or  possibly  more  in  the  distal  row. 
While  the  arrangement  of  these  interbrachial  plates  is  different  than 
hi  the  other  species  of  Petraster,  their  position  is  that  of  this  genus. 
Therefore  this  species  is  for  the  present  referred  to  Petraster.  The 
preservation  of  this  specimen  is  such  that  its  generic  and  specific 
characters  will  remain  hi  obscurity  until  other  material  is  found. 
It  lies  with  the  actinal  side  buried  in  the  limestone  while  all  of  the 
abactinal  plates  have  been  worn  away.  What  one  sees  is  therefore 
the  inner  or  dorsal  aspect  of  the  ventral  skeleton. 

PETRASTER  SMYTHI  McCoy. 

Petraster  smythi  McCoy,  Geol.  Surv.  Victoria,  Prodr.  Pal.  Victoria,  dec.  ],  1874, 
p.  41,  pi.  10,  figs.  1-16. 

Original  description. — "Five  broad  semielliptical  lobes  meeting 
at  slightly  rounded  reentering  angles,  leaving  the  length  and  the 


148  BULLETIN   88,  UNITED   STATES   NATIONAL  MUSEUM. 

width  at  base  of  the  rays  nearly  equal  and  less  than  the  width  of  the 
disk.  The  upper  surface  is  covered  with  crowded  irregularly  polyg- 
onal tumid  plates.  Madreporiform  tubercle  very  large  (1J  lines  in 
diameter),  irregularly  porous,  and  rugged  with  branching  vermicular 
ridges,  excentric  toward  base  of  the  two  posterior  rays.  Ambulacral 
groove  very  narrow,  bordered  with  a  row  of  large  transversely  oblong 
adambulacral  plates,  wider  than  long,  about  6  in  2  lines  at  middle 
of  ray;  margin  of  the  rays  bordered  with  a  rather  smaller  row  of 
similar  marginal  plates;  between  the  row  of  adambulacral  and  mar- 
ginal plates  an  intercalary  row  of  small  irregular  plates.  Width  of 
disk  between  the  rays,  7  lines;  from  tip  to  tip  of  rays,  about  1  inch  2 
lines;  length  of  ray,  about  5£  lines. 

"  Very  rare  in  the  fine  sandy  Upper  Silurian  rocks  of  Moonee  Ponds, 
Flemington,  a  little  north  of  Melbourne  [Australia]. ' ' 

Remarks. — The  holotype  exposes  the  abactinal  side,  but  the  plates 
of  two  of  the  rays  are  absent,  exposing  the  actinal  skeleton,  which  is 
therefore  seen  from  its  inner  side.  So  far  as  one  can  judge  of  the 
description  and  illustration,  the  species  is  a  small  but  genuine  Petras- 
ter.  Abactinally  the  rays  have  conspicuous  radial  and  supramar- 
ginal  columns,  each  with  about  17  ossicles,  that  are  tumid  and  are 
all  closely  adjoining.  Outside  of  these  in  the  distal  portion  of  the 
rays  are  the  equally  conspicuous  inframarginals,  and  they  margin 
not  only  these  parts  but  the  entire  animal;  proximally  the  inframar- 
ginals  separate  more  and  more  from  the  supramarginals,  forming 
small  ambital  areas,  occupied  by  a  number  (can  not  be  determined) 
of  rounded  plates  that  now  appear  not  to  have  been  closely  adjoining. 

Madreporite  large,  radiately  striate,  situated  in  an  interradius  and 
well  inside  the  ambital  area. 

Ambulacralia  large,  about  12  in  a  column,  and  opposite  one  another. 
Adambulacrals  smaller,  about  14  in  a  column.  Interbrachial  struc- 
ture unknown. 

Genus  LINDSTROMASTER  Gregory. 

Lindstromaster  GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6, 1899,  pp.  344,  346. 
Hisingeraster  STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56,  1900, 
pp.  224,  225  (same  genoholotype  as  for  Lindstromaster). 

Original  description. — "Palseasterinidae  with  flat  pentagonal  disk 
and  five  short  blunt  rays. 

''The  plates  of  the  disk  are  large,  polygonal,  tuberculate,  and 
crowded  into  a  close  tessellate  pavement,  which  completely  covers 
the  interradial  areas. 


REVISION   OF   PALEOZOIC    STELLEROIDEA.  149 

"Marginal  [inframarginal]  plates  well  developed  and  conspicuous, 
and  but  slightly  smaller  than  the  adambulacrals.  Both  supra-  and 
inframarginals  appear  to  be  present. 

"The  abactinal  [actinal]  furrows  are  large  and  subpetaloid.  They 
are  bounded  by  large  tuberculate  adambulacral  plates.  The  ambu- 
lacral  plates  are  boot-shaped  [and  slightly  alternating].  The  pores 
for  the  podia  are  large,  and  occur  on  the  suture  between  the  adam- 
bulacrals and  ambulacrals. 

"The  adambulacral  elements  in  the  oral  armature  are  prominent, 
and  consist  of  five  pairs  of  subtriangular  plates. 

"Type-species:  Asterias  antiqua,  Hisinger  1837.  Silurian:  Got- 
land." No  other  species  of  this  genus  is  known. 

Remarks. — Of  this  genus  only  the  actinal  side  is  known  and  the 
published  figure  from  a  drawing  by  Mr.  George  Lilejevall  is  one  of 
the  best  of  Paleozoic  starfishes.  Lindstromaster  differs  from  Petras- 
ter  in  but  one  generic  character,  if  it  be  a  generic  one,  in  that  the 
ambulacral  furrows  are  large  and  subpetaloid  in  the  former  and 
narrow  and  slowly  tapering  in  Petraster.  However,  since  the  abac- 
tinal area  is  unknown  in  Lindstromaster  there  probably  will  be  dis- 
covered in  this  area  differences  distinguishing  it  from  Petraster.  It 
is  also  probable  that  the  marginals  in  Lindstromaster  which  Gregory 
thinks  are  "both  supra-  and  inframarginals"  lying  directly  super- 
posed are  only  inframarginals.  In  Siluric  starfishes  these  plates 
have  not  attained  the  superposed  position  so  marked  in  recent  genera. 
The  supramarginals  are  here  never  true  marginals  and  always  lie 
more  or  less  inside  the  inframarginals,  which  are  the  true  marginals  of 
these  early  genera.  For  other  remarks  see  Palseostella. 

The  name  Hisingeraster  was  published  after  Gregory's  name  and 
is  based  on  the  same  genotype. 

When  more  material  is  obtained  and  the  genus  is  restudied,  com- 
parisons should  also  be  made  with  Palasterina  primseva,  as  the  two 
forms  appear  to  have  much  in  common. 

LINDSTROMASTER  ANTIQUT7S  (Hisinger). 

Asterias  antiqua  HISINGER,  Lethsea  Suecia,  1837,  p.  89,  pi.  26,  fig.  6. 
Lindstromaster  antiqua  GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6,  1899,  pp.  343,  347, 

pi.  36,  figs,  la,  16  (complete  synonymy  given  here). — SCHONDORF,  Jahrb. 

nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63,  1910,  p.  225. 

A  single  specimen  is  known  from  "Bed  C,"  Mount  Hoburg,  Got- 
land, corresponding  to  the  Wenlock  of  England.  It  is  in  the  Angelin 
collection  of  the  Mineralogical  Museum  at  Copenhagen. 


150  BULLETIN   88,  UNITED   STATES   NATIONAL  MUSEUM. 

Genus  PALASTERINA  McCoy. 

Palasterina  McCoY,  British  Pal.  Foss.,  1851,  p.  59  (not  defined).— SALTER,  Ann. 
Mag.  Nat.  Hist.,  ser.  2,  vol.  20,  1857,  pp.  324,  327.— BILLINGS  (part),  Geol. 
Surv.  Canada,  Can.  Org.  Rem.,  dec.  3,  1858,  p.  76.— ZITTEL,  Handb.  Pal., 
vol.  1, 1879,  p.  453.— STURTZ  (part),  Palseontographica,  vol.  36,  1890,  p.  226; 
(part),  Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50,  1893,  pp.  43,  60.— 
SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63,  1910, 
p.  220. 

Palxasterina  GREGORY,  Geol.  Mag.,   dec.  4,   vol.   6,    1899,    p.   349  (complete 
synonymy  here). 

The  term  Palasterina  was  used  by  McCoy  in  the  following  words: 
"Before  I  was  aware  Prof.  Forbes  had  described  them  [the  three 
species  named  below]  it  seemed  to  me  that  the  U  [rasterella]  ruthveni 
and  U.  Jvirudo,  as  well  as  the  similar  American  species,  might  be  easily 
separated  from  the  great  starfishes  forming  the  recent  genus  Uraster, 
by  their  small  size  and  much  more  simple  skeletons,  and  I  had  named 
the  genus  Urasterella  in  my  manuscript.  The  U.  primdevus  I  thought 
generically  distinct  from  the  other  two,  as  the  rays  were  not  contracted 
at  base,  etc.;  and  I  had  named  it  Palasterina,  from  its  resemblance 
to  the  recent  genus  Asterina." 

The  three  species  mentioned  by  McCoy  had  been  described  by  him 
in  manuscript,  but  on  learning  that  descriptions  had  been  previously 
published  by  Forbes,  the  former,  in  his  "British  Palaeozoic  Fossils/' 
adopted  the  names  of  Salter.  In  writing  of  these  three  forms,  as 
above  quoted,  he  uses  the  generic  name  Palasterina  (not  Palseasterina, 
the  generally  accepted  form),  and  while  a  type-species  is  selected,  yet 
McCoy  did  not  point  out  a  single  generic  character  of  present  value. 
His  statement  that  "the  rays  were  not  contracted  at  base"  is  a 
feature  which  at  that  time  distinguished  Palasterina  from  Urasterella, 
but  now  many  Paleozoic  genera  are  known  having  rays  "not  con- 
tracted at  base." 

While  McCoy  does  not  strictly  propose  the  generic  name,  Salter  is 
the  first  to  accept  and  define  Palasterina,  which  he  does  in  the  following 
words : 

"Pentagonal,  depressed,  the  arms  a  little  produced,  with  three  or 
five  principal  rows  of  tubercles  above,  combined  with  a  plated  disk 
which  fills  .up  the  angles ;  ambulacra  rather  shallow,  of  subquadrate 
or  slightly  transverse  ossicles,  bordered  by  a  single  row  of  squarish 
large  plates,  the  lowest  of  which  (ad-oral  adambulacral  plates,  Huxley; 
angle-ossicula,  Forbes)  are  large  and  triangular,  bearing  combs  of 
spines  (Upper  Silurian)." 

Recently  Gregory,  in  a  paper  entitled  "On  Lindstromaster  and  the 
classification  of  the  Palseasterids"  (1899),  redefines  the  genus,  basing 
his  definition  largely  on  P.  lonneyi.  In  this  connection  he  writes: 

"The  species  [P.  lonneyi]  is  of  interest,  as  the  structure  is  better 
preserved  than  in  the  type  of  the  genus  [P.  primseva],  and  thus  we  are 


KEVISION   OF   PALEOZOIC    STELLEKOIDEA.  151 

largely  dependent  upon  it  for  our  knowledge  of  the  generic  charac- 
ters "  (p.  350). 

Emended  description. — Disk  large,  with  moderately  developed  inter- 
brachial  arches.  Rays  five,  short,  and  tapering  more  or  less  rapidly. 
UR  about  twice  as  great  as  r." 

Abactinal  area  of  rays  distally  with  one  medial  column  of  large, 
thick,  and  subquadrangular  radial  plates,  on  each  side  of  which  are 
similar  columns  of  supramarginal  and  inframarginal  pieces.  In  this 
region  the  columns  adjoin  and  the  ossicles  are  crowded,  but 
proximally  between  the  radial  and  supramarginal  and  between  the 
latter  and  the  inframarginal  columns  (ambital  areas)  are  inserted 
numerous  accessory  smaller  plates.  The  latter  are  most  numerous 
in  the  ambital  areas  and  at  the  base  of  the  rays.  The  ossicles  are 
packed  into  a  tessellate  pavement.  In  the  center  of  the  disk  there 
seems  to  be  a  prominent  central  disk  piece  and  at  the  bases  of  the 
rays  there  is  a  somewhat  disconnected  ring  of  ten  most  prominent 
plates,  the  five  basal  pieces  of  the  radial  and  five  interradial  that 
give  rise  to  the  ten  supramarginal  columns.  Inside  of  this  ring  there 
are  probably  numerous,  very  small  pieces  with  no  definite  arrange- 
ment. A  number  of  the  proximal  plates  of  both  the  radial  and 
supramarginal  columns  may  be  separated  from  one  another  by  small 
accessory  pieces. 

Madreporite  abactinal. 

Inframarginal  plates  bounding  the  entire  outer  edge  and  common  to 
both  sides  of  the  animal.  These  plates  are,  however,  small  (smaller 
than  the  adambulacrals)  and  bear  tufts  of  small  spines. 

Adambulacrals  subquadrangular,  and  closely  adjoining,  each  plate 
bearing  on  its  outer  lateral  edge  a  tuft  of  three  spines.  Oral  armature 
consists  of  five  pairs  of  triangular  adambulacral  plates  which  have 
slender  spines  on  the  inner  edges. 

Interbrachial  areas  extending  to  near  the  distal  ends  of  rays  and 
occupied  by  numerous  "isolated  rounded  or  subangular  [accessory 
interbrachial]  plates  bearing  [single]  small  spines." 

Ambulacrals  slightly  alternating  and  about  as  numerous  as  the 
adambulacrals.  Each  plate  has  an  L-shaped  ridge,  posteriorly 
directed.  The  podial  openings  are  on  the  sutures  between  the 
ambulacrals  and  adambulacrals. 

Genoholotype. —  Uraster  prims&vus  Forbes.  The  above  diagnosis  is, 
however,  based  largely  upon  Palasterina  bonneyi  Gregory.  Dr. 
Bather  sent  the  writer  a  number  of  wax  squeezes  of  the  genoholo- 
type,  and  while  the  parts  preserved  are  clear  and  sharp,  yet  the  speci- 
mens are  not  complete  enough  to  work  out  the  generic  characters. 
Therefore,  for  the  present,  P.  bonneyi  is  taken  as  the  genoholotype. 

Distribution. — Ludlow  shales  (Upper  Siluric)  of  Great  Britain. 


152  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

Contains : 

P.  primseva  (Forbes).    Ludlow  of  England. 
P.  bonneyi  Gregory.     Ludlow  of  England. 
P.  (?)  ramseyensis  Hicks.     Tremadoc  of  Wales. 

For  other  remarks  see  Palseostella. 

Since  the  foregoing  was  written,  Schondorf 's  work  cited  above  has 
come  to  hand.  He  studied  wax  squeezes  of  P.  primseva  and  deter- 
mined that  the  genotype  is  devoid  of  marginalia,  and  therefore  refers 
Palasterina  to  the  Cryptozonia.  He  writes:  " Special  marginalia  ap- 
pear not  to  be  present,  at  least  the  marginal  rows  are  in  no  way  dis- 
tinguishable from  the  other  intermediary  [accessory  interbrachial] 
plates.  Accordingly  Palasterina  primseva  Forbes  sp.  does  not  belong 
as  stated  by  Gregory  (p.  349)  to  the  asterids  with  distinct  marginal 
plates,  the  Phanerozonia,  but  with  the  asterids  having  inconspicuous 
or  no  marginalia,  the  Cryptozonia'7  (p.  222). 

The  present  writer  holds  that  there  are  inframarginalia  present  all 
along  the  edge  of  the  interbrachial  areas  and  the  rays,  and  that  they 
are  most  typical  along  the  distal  portion  of  the  rays.  Here  the 
inframarginalia  are  ontogenetically  youngest  and  less  affected  by 
subsequent  growth  displacement  and  alteration  than  are  the  older 
ones  in  the  interbrachial  areas.  In  the  latter  region  it  is  true  that 
the  marginalia  are  not  conspicuous,  but  so  long  as  one  can  make 
them  out  to  be  inframarginalia,  size  alone  can  not  be  the  criterion 
that  will  permit  of  the  conclusion  that  no  marginalia  are  present  in 
Palasterina.  However,  the  difference  in  interpretation  between 
Schondorf  and  the  writer  is  not  a  great  one,  as  neither  lays  great 
taxonomic  value  on  whether  the  marginalia  are  prominent  or  unot 
prominently  developed"  (p.  223).  So  long  as  the  inframarginalia  are 
more  or  less  prominent,  one  of  the  generic  characters  of  Palasterina, 
a  phanerozonian,  is  present,  and  when  they  are  so  inconspicuous  as 
not  to  be  made  out  among  the  other  ossicles,  we  have  one  of  the 
generic  characters  of  Schuchertia,  a  cryptozonian. 

Schondorf  also  states  that  the  ambulacralia,  and  the  adambulacralia 
as  well,  are  all  opposite  and  do  not  alternate  with  one  another.  The 
present  writer  states  that  the  ambulacrals  are  "  slightly  alternating,  "H 
and  throughout  this  work  he  has  given  the  arrangement  of  these 
ossicles  his  special  attention.  In  a  great  many  cases,  and  especially 
in  the  Ordovicic  species,  he  has  had  difficulty  in  ascertaining  what 
was  their  actual  position  in  the  living  animals,  for  nearly  all  the 
fossils  have  been  squeezed  more  or  less.  He  has  always  given  their 
arrangement  as  they  impressed  him  in  the  fossil  when  no  evident  dis- 
tortion could  be  seen.  The  writer  would  not  lay  special  stress  upon 
slight  alternation  among  the  ambulacralia,  for  in  many  Ordovicic 
species  there  is  some  variation  in  each  ray  from  opposite  to  slightly , 
alternate.  Of  course,  when  the  alternation  or  opposite  arrangement 


REVISION'   OF  PALEOZOIC   STELLEROIDEA.  153 

is  complete  and  fixed  throughout  the  rays,  he  would  lay  great  value 
on  the  character.  It  may  be  said  that  in  the  earliest  Asteroidea  the 
chronogenetic  tendency  is  from  slight  alternation  to  complete  and 
fixed  opposite  arrangement  among  the  amhulacral  ossicles. 

PALASTERINA  PRIM^EVA  (Forbes). 

Uraster  primxvus  FORBES,  Mem.  Geol.  Surv.  Great  Britain,  vol.  2,  pt.  2,  1848, 
p.  463;  Mem.  Geol.  Surv.  United  Kingdom,  dec.  1,  1849,  p.  2,  pi.  1,  figs. 
2a,  26;  in  McCoy,  Brit.  Pal.  Foss.,  1851,  p.  60.— MURCHISON,  Siluria,  1854, 
p;  221,  fig.  39. 

Palasterina  primxvus  McCoy,  Brit.  Pal.  Foss.,  1851,  p.  59  (nomen  nudum). — 
SALTER,  Ann.  Mag.  Nat.  Hist.,  ser.  2,  vol.  20,  1857,  p.  327,  pi.  9,  figs.  2a-2c.— 
WRIGHT,  Mon.  British  Foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1  (Palseontogr. 
Soc.  for  1861),  1862,  p.  26,  fig.  16a.— QUENSTED,  Petrefactenkunde  Deutsch- 
lands,  vol.  4,  1876,  p.  74,  pi.  92,  fig.  35.— STURTZ,  Verh.  naturh.  Ver.  preuss. 
Rheinl.,  etc.,  vol.  50,  1893,  p.  44;  vol.  56,  1900,  pp.  214,  224.— SCHONDORF, 
Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63,  1910,  p.  220. 

Palszasterina  primseva  GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6,  1899,  p.  349. — SPEN- 
CER, Mon.  Brit.  Pal.  Asterozoa,  pt.  1  (Palseontogr.  Soc.  for  1913),  1914,  pp. 
37,  38,  fig.  30. 

Formation  and  locality. — A  common  species  in  the  Ludlow  rocks. 
Underbarrow,  Kendal,  Westmoreland,  and  Leintwardine,  Shropshire, 
England. 

Remarks. — Dr.  Bather  furnished  the  author  with  wax  squeezes  of 
specimens  Nos.  E4990-E4993  (E61  is  quite  another  species  and 
abactinally  more  closely  related  to  Eudsonaster)  in  the  British 
Museum  (Natural  History).  They  are  from  the  Lower  Ludlow  at 
Kendal,  Westmoreland.  These  show  little  of  value  abactinally,  but 
actinally  are  well  preserved  along  the  ambulacra.  Unfortunately, 
however,  none  of  the  marginals  are  present  and  but  little  of  the 
interbrachial  areas.  When  better  material  is  at  hand  a  comparison 
should  be  made  also  with  Lindstrb'master  antiquus  (Hisinger),  as  the 
two  look  suspiciously  alike. 

PALASTERINA  BONNEYI  Gregory. 

Palseasterina  bonneyi  GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6,  1899,  pp.  349,  350, 
text  figs.  1-3,  and  pi.  16,  figs.  2a,  26. — SCHONDORF,  Jahrb.  nassauisch.  Ver. 
Naturk.,  Wiesbaden,  vol.  63,  1910,  p.  223. 

"This  species  has  hitherto  been  included  in  P.  primseva,  the  type- 
species  of  the  genus,  from  which  it  differs  by  having  shorter  and 
blunter  rays,  more  numerous  actinal  interbrachial  plates,  and  more 
adambulacral  plates  in  each  series ;  the  character  of  the  abactinal  ray 
plates  is  also  different  in  the  species,  the  longitudinal  series  being 
widely  separated  at  the  proximal  end  of  the  rays  in  P.  bonneyi" 
(Gregory). 

Formation  and  locality. — Ludlow  shales.  Leintwardine,  Shrop- 
shire. Types  in  British  Museum  (Natural  History). 


154  BULLETIN   88,   UNITED   STATES   NATIONAL  MUSEUM. 

PALASTERINA  (?)  RAMSEYENSIS  Hicks. 

Palasterina  ramseyensis  HICKS,  Quart.  Journ.  Geol.  Soc.  London,  vol.  29,  1873, 
p.  51,  pi.  4,  figs.  21-23.— WOODWARD,  Geol.  Mag.,  dec.  2,  vol.  1,  1874,  p.  96. 

This  starfish  needs  to  be  restudied  in  the  light  of  modern  knowl- 
edge. The  specimens  represented  by  Hicks's  figures  21  and  22  seem 
to  be  referable  to  Petraster  rather  than  to  Palasterina,  while  that  of 
figure  23  appears  to  be  nearer  Mesopalseaster. 

Formation  and  locality. — Said  to  be  from  the  Tremadoc,  but  the 
development  of  the  starfish  seems  to  be  in  harmony  with  Upper 
Ordovicic  time.  The  specimens  are  from  Ramsey  Island  and  St. 
Davids,  Wales,  and  are  in  Mr.  Lightbody's  collection. 

Genus  URANASTER  Gregory. 

Uranaster  GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6,  1899,  p.  347.— SCHONDORF,  Jahrb. 
nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63,  1910,  p.  225. 

The  name  is  "from  Uranus,  the  grandfather  of  Pluto;  the  starfish 
resembles  the  living  genus  Plutonaster." 

Generic  description. — Animal  deeply  pentagonal,  above  medium  size, 
with  well-developed  interbrachial  arches,  and  five  long  slender  rays. 

Inframarginal  plates  marginal,  large,  and  elongated  in  the  direction 
of  the  rays.  These  plates  are  apparently  common  to  both  the  actinal 
and  abactinal  areas.  Abactinally  adjoining  the  inframarginals  is 
another  column  of  large  submarginal  plates  ( ?supramarginals) 
alternating  with  the  former,  and  sometimes  there  are  smaller  acces- 
sory pieces  between  these  columns  in  the  angles  of  the  plates.  The 
rays  have  no  medial  or  radial  columns  of  prominent  plates,  but  the 
entire  space  between  the  submarginal  columns  is  occupied  by  numer- 
ous closely  fitting,  convex,  or  tubercular  plates  which  are  arranged 
in  alternate  transverse  rows,  each  having  from  three  to  four  pieces 
on  each  side  of  a  ray. 

Interbrachial  accessory  plates  numerous,  polygonal,  and,  according 
to  Baily 's  figure  of  U.  Tcinahani,  arranged  in  crescentic  rows  conforming 
to  the  shape  of  the  disk  margin.  These  plates  do  not  appear  to 
extend  between  the  marginals  and  adambulacrals  beyond  the  mid- 
length  of  the  rays. 

Adambulacral  plates  tubercular,  subquadrangular  in  outline,  and 
widest  transversely  in  the  medial  third  of  the  column. 

Ambulacral  furrows  very  narrow,  deep,  and  tapering  gradually. 
Ambulacra!  plates  traversed  by  strong  transverse  ridges. 

Madreporite  unknown. 

GenoJiolotype. — Palasterina  Icinahani  Baily.  Upper  Ordovicic.  A 
second  species  is  U.  elizse,  Spencer,  also  from  the  Ordovicic  of  Great 
Britain. 

Remarks. —  Uranaster  differs  from  Petraster,  Palasterina,  and 
Lindstromaster  in  having  the  abactinal  area  of  the  rays  between  the 


REVISION    OF   PALEOZOIC    STELLEROIDEA.  155 

two  pairs  of  marginal  columns  filled  with  small  tuberculate  plates 
arranged  in  transverse  rows.  The  other  genera  have  the  plates  in 
longitudinal  columns. 

URANASTER  KINAHANI  (Baily). 

Palasterina  kinahani  BAILY,  in  KINAHAN,  Man.  Geol.  Ireland,  1878,  pp.  xv,  26, 
pi.  2,  fig.  1;  Mem.  Geol.  Surv.  Ireland,  Expl.  Mem.  Sheets  Nos.  169,  170, 
180,  181,  1879,  pp.  58,  59,  fig.  6. 

Uranaster  kinahani  GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6, 1899,  p.  348. — SCHONDORP, 
Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63,  1910,  p.  225. 

This  species  occurs  abundantly  as  natural  molds  in  the  Caradoc 
(Upper  Ordovicic),  near  Ballymadder  Point  and  Bannow,  Wexford, 
Ireland.  A  specimen  is  in  the  British  Museum  (Natural  History), 
No.  E  194. 

URANASTER  ELIZAS  Spencer. 

Uranaster  elizx  SPENCER,  Mon.  Brit.  Pal.  Asterozoa,  pt.  1  (Palaeontogr.  Soc.  .for 
1913),  1914,  pp.  18,  20,  23,  figs.  18,  23. 

From  the  Ordovicic  of  Great  Britain. 

Genus  PAL^OSTELLA  Stiirtz. 

Palxostella  STURTZ,  Palseohtographica,  vol.  36,  1890,  p.  230,  pi.  31,  figs.  42,  43; 

Verb,  naturb.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50, 1893,  pp.  42,  58,  pi.  1,  figs.5^8, 
Palsenectria  STURTZ,   Verb,  naturb.   Ver.  preuss.  Rbeinl.,  etc.,  vol.  50,  1893. 

p.  12  (genoholotype  the  second  specimen  of  Palseostella  solida). 

Description. — Animal  attaining  a  large  size,  with  large  pentagonal 
interbrachial  arcs.  Rays  five,  stout.  Ambulacral  grooves  wide  and 
apparently  regularly  tapering. 

Abactinally  the  inframarginals  are  also  the  marginals  for  this 
area.  Near  the  distal  ends  of  the  rays  the  supramarginals  adjoin 
and  lie  either  partially  over  or  inside  of  the  inframarginals  and 
continue  nearly  to  the  axillae.  There  also  seems  to  be  a  single  radial 
column,  confined,  however,  to  the  distal  third  of  the  rays.  Other- 
wise the  abactinal  skeleton  consists  of  very  numerous,  small,  irregu- 
larly shaped,  loosely  interlocking  plates  without  definite  arrangement. 

Madreporite  abactinal. 

Actinally  the  animal  is  bounded  by  subquadrate,  numerously 
spine-bearing,  inframarginal  plates  which  increase  rapidly  in  size 
towards  the  axillae,  where  they  are  ponderous  and  nearly  twice  as 
wide  as  long.  Ambulacral  plates  alternating,  L-shaped,  with  single 
columns  of  podial  openings.  Adambulacrals  subquadrate,  prominent, 
increasing  regularly  in  width  proximally  and  bearing  spines  like 
the  marginals.  Interbrachial  areas  large,  reaching  to  near  the 
distal  ends  of  rays,  widely  separating  the  inframarginals  from  the 
adambulacrals  in  the  axillary  region,  and  the  space  occupied  by 
very  numerous,  small,  spine-bearing,  apparently  irregularly  dis- 
posed plates. 


156  BULLETIN   88,  UNITED   STATES   NATIONAL   MUSEUM. 

Genoholotype  and  only  species. — P.  solida  Stiirtz.  Two  speci- 
mens are  known  from  the  Lower  Devonic  roofing  slates,  Bundenbach, 
Germany. 

Remarks. — The  starfishes  from  the  Bundenbach  roofing  slates  are 
at  best  but  poor  fossils  and  were  it  not  for  the  great  skill  of  Mr. 
Stiirtz  in  cleaning  them  out  of  the  matrix  their  systematic  position 
could  not  well  be  determined.  At  best  they  are  compressed  to  almost 
paper  thickness  and  distorted  during  solidification  and  shortening  or 
elongation  of  the  slates.  Under  these  circumstances  it  appears 
best  to  redescribe  the  detailed  abactinal  characters  as  given  by 
Stiirtz.  He  mentions  numerous  paxillae  and  finds  many  characters 
common  to  both  Palseostella  and  the  living  Nectria. 

Palseostella  is  closely  related  to  Palasterina,  also  to  Lindstromaster , 
and  may  be  a  descendant  of  the  latter.  The  actinal  structure  in 
Lindstromaster  and  Palseostella  is  nearly  alike,  both  having  large 
inframarginals  and  adambulacrals,  but  the  interbrachial  areas  in 
the  former  are  occupied  by  large  closely  adjoining  plates,  while  in  the 
latter  these  are  small  and  somewhat  loosely  interlocking.  Abac- 
tinally  they  can  not  be  compared,  since  that  side  is  unknown  in 
Lindstromaster.  The  greatest  difference  between  Palasterina  and 
Palseostella  is  that  the  former  has  small  inframarginals  while  in  the 
latter  they  are  very  large.  Then  the  supramarginal  and  radial 
columns  in  Palasterina  are  better  developed  and  comparatively 
larger,  while  in  Palseostella  they  are  shorter  and  most  prominent  in 
the  distal  half  of  the  rays.  In  the  latter  genus  the  central  region 
of  the  disk  has  no  ring  of  fifteen  basal  radial  and  supramarginal 
plates  as  in  Palasterina. 

From  this  evidence  it  seems  probable  that  the  line  of  descent  is 
from  Petraster  to  Lindstromaster  to  Palseostella  in  marntaining  promi- 
nent columns  of  inframarginals,  while  the  line  from  Petraster  to 
Palasterina  tends  toward  the  reduction  or  elimination  of  these  plates 
as  a  conspicuous  skeleton  element. 

Palsenectria  is  based  on  the  second  specimen,  and  the  genus  is 
described  as  follows:  " Should  the  described  starfish  [the  second 
specimen  of  Palseostella  solida  Stiirtz]  prove  not  to  be  identical  with 
Palseostella,  which  is  possible,  even  though  not  probable — the  other 
specimen  is  in  the  British  Museum — I  propose  for  it  the  new  name 
Palsenectria  devonica."  Unless  the  author  takes  the  time  to  work 
out  his  new  forms,  or  decides  the  problem  presented  for  himself,  he 
should  not  expect  some  one  else  to  do  this  for  him.  Under  these 
circumstances  the  genus  and  species  are  regarded  as  not  defined. 

Genus  PSEUDOPALASTERINA  Sturtz. 

Pseudopalasterina  STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56,  1900, 
pp.  219,  224. 

Genoholotype  and  only  species. — Palasterina  follmanni  Sturtz. 


REVISION    OF   PALEOZOIC    STELLEROIDEA.  157 

PSEUDOPALASTERINA  FOLLMANNI  (Sttirtz). 

Palasterina  follmanni  STURTZ,  Paleeontographica,  vol.  36,  1890,  p.  226,  pi.  29, 

figs.  29-31a. 
Pseudopalasterina  follmanni  STURTZ,  Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.. 

vol.  56,  1900,  pp.  219,  224. 

Actinally  this  species  has  ambulacrals  and  narrow  adambulacrals 
and  outside  of  the  latter  the  interbrachial  and  abactinal  areas  consist 
of  a  membrane  with  small  spine-bearing  plates.  It  has  no  inframar- 
ginal  nor  radial  and  supramarginal  columns,  features  characterizing 
Palasterina. 

Formation  and  locality. — Lower  Devonic  of  Bundenbach,  Germany. 

NEW  GENUS. 

NEW  SPECIES. 

Prof.  Weller  got  on  Fountain  Creek,  at  Waterloo,  Illinois,  in  the 
St.  Louis  limestone,  a  small  pentagonal  asterid  (No.  14396,  Univer- 
sity of  Chicago  collection)  showing  only  the  actinal  side,  that  differs 
from  all  other  known  forms  of  the  large-disked  genera.  The  five  rays 
are  completely  within  the  pentagon,  with  the  interbrachial  areas  large 
and  straight-sided.  These  areas  are  made  up  of  a  few  large  tesselate 
plates,  of  which  it  seems  that  seven  compose  the  interbrachial  mar- 
gins and  inside  these  there  seem  to  be  transverse  rows,  each  with  five, 
three,  two,  and  one  ossicles.  It  could  not  be  made  out  whether  the 
inframarginals  and  supramarginals  are  directly  superposed,  but  this 
may  be  so. 

Ambulacral  furrows  exceedingly  narrow,  a  mere  line.  These  are 
bounded  by  columns  of  large,  very  ornate  adambulacrals,  each  with 
seven  ossicles.  Those  of  opposite  columns  alternate  decidedly  with 
one  another  and  on  its  outer  side  each  bears  two  short  but  dis- 
tinct spines. 

Adambulacral  oral  armature  in  five  very  prominent  pairs  of  pieces, 
long  and  pointed,  and  about  twice  as  long  as  any  other  adambulacrals. 

Measurements:  R  =  8.5  mm.,  r  =  7  mm. 

Family  LEPIDASTERIME  Gregory  (emend.). 

Lepidasteridse  GREGORY  (part),  Geol.  Mag.,  dec.  4,  vol.  6,  1899,  p.  352  (includes 
Lepidaster&n&Etheridgaster)',  Treat.  Zool.,  vol.  3,  Echinoderma,  1900,  p.  255. 

Helutnihasterinse  GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6,  1899,  p.  258. 

Helianihasteridse  STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56,  1900, 
p.  204. — SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63, 
1910,  p.  235. 

Primitive  multi-rayed  Phanerozonia  apparently  with  the  general 
structure  of  Pabeasteridse,  but  with  as  many  as  24  rays.  Madreporite 
known  only  in  Helianthaster,  where  it  is  interbrachial  and  on  the 


158  BULLETIN    88,   UNITED   STATES   NATIONAL   MUSEUM. 

edge  of  the  disk,  more  actinal  than  abactinal.    Inframarginals   or 
supramarginals  bounding  the  rays. 
Contains : 
Lepidaster  Forbes. 
Eelianthaster  Koemer. 
Lepidaster ella,  new  genus. 

Remarks. — For  a  discussion  as  to  why  there  are  multi-rayed — that 
is,  more  than  the  normal  five-rayed — asterids,  see  the  family  Palse- 

osolasteridse. 

Genus  LEPIDASTER  Forbes. 

Lepidaster  FORBES,  Mem.  Geol.  Surv.  United  Kingdom,  British  Org.  Hem., 
dec.  3,  1850,  p.  1,  pi.  1,  figs.  1-3.— WRIGHT,  Mon.  British  Foss.  Echinod., 
Oolitic,  vol.  2,  pt.  1  (Palseontogr.  Soc.  for  1861),  1862,  p.  35.— WOODWARD, 
Geol.  Mag.,  dec.  2,  vol.  1,  1874,  p.  9.— ZITTEL,  Handb.  Pal.,  vol.  1,  1879, 
p.  454.— STURTZ,  Palseontographica,  vol.  36,  1890,  p.  222,  pi.  28,  figs.19-20; 
Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50,  1893,  pp.  52,  72. 

Generic  description. — Disk  very  large,  over  50  mm.  in  diameter, 
and  apparently  composed  of  heavy,  closely  set,  polygonal  plates. 
Rays  13  in  number,  fairly  stout,  not  slender,  and  tapering  fairly 
rapidly  in  the  distal  half.  R  =  52  mm. ,  r  =  25  mm.  A  little  more  than 
half  the  length  of  the  rays  extends  beyond  the  disk. 

Actinally,  the  rays  are  bounded  on  each  side  of  the  very  narrow 
ambulacral  furrow  by  two  columns  of  strong,  tumid,  closely  ad- 
joining, transversely  oblong,  adambulacral  and  inframarginal  plates. 
The  latter  are  also  the  marginals  for  the  abactinal  side.  The  adam- 
bulacrals  are  tuberculate  and  probably  bore  small  spines;  there 
are  25  ossicles  in  each  column.  Ambulacrals  unknown,  but  the 
arrangement  of  the  adambulacrals  indicates  that  they  were  slightly 
alternate. 

Madreporite  and  interbrachial  areas  unknown. 

Abactinally  little  is  known.  The  rays  are  described  as  having 
"  numerous  small  polygonal  nearly  flat  ossicula,  closely  set,  and  of 
various  sizes."  To  judge  by  similar  rays  in  other  genera,  it  would 
appear  that  Lepidaster  may  have  had  radial  and  supramarginal 
columns  of  ossicles. 

Genoholotype  and  only  species. — L.  grayi  Forbes.  The  holotype 
was  found  in  the  quarries  of  Wenlock  limestone  in  the  Castle  Hill  at 
Dudley,  England. 

Observations. — Forbes's  illustration  leads  the  writer  to  believe 
that  the  abactinal  plates  have  been  deranged  and  that  originally 
the  larger  pieces  were  arranged  in  supramarginal  columns,  while  the 
smaller  ones  composed  the  radial  row  of  ossicula.  This  type  of 
structure  generally  goes  with  the  actinal  arrangement  as  here  seen  in 
Lepidaster ,  a  duplicate  of  the  same  structure  in  Hudsonaster}  Poise- 
aster,  and  Mesopalseaster.  Stiirtz  compares  the  abactinal  skeleton  of 


REVISION   OF  PALEOZOIC   STELLEEOIDEA.  159 

Lepidaster  with  the  recent  ScytJiaster,  which  is  made  up  of  plates  of 
various  sizes  without  regular  arrangement.  It  seems  more  natural 
to  compare  Lepidaster  with  Siluric  and  Ordovicic  genera  than  with 
recent  forms,  and  particularly  when  nearly  identical  structures  are 
found  in  the  genera  mentioned. 

Forbes  also  describes  Lepidaster  as  having  the  ambulacral  grooves 
"  towards  the  extremity,  in  some  instances  partially  filled  up  by  small 
polygonal  intervening  plates."  His  figures  show  a  few  of  these 
plates  arranged  in  single  columns.  This  anomalous  structure  is 
undoubtedly  best  explained  by  accepting  Stiirtz's  conclusion,  that 
they  are  the  separated  ambulacral  pieces,  since  otherwise  none  of 
these  plates  appear  to  be  present.  As  a  fifth  actinal,  or  a  single 
ambulacral  column,  the  structure  is  out  of  all*  harmony  with  star- 
fishes. 

Genus  HELIANTHASTER  Roemer. 

Eelianthaster  ROEMER,  Palseontographica,  vol.  9, 1863,  p.  147,  pi.  28. — QUENSTEDT, 
Petrefactenkunde  Deutschlands,  vol.  4,  1876,  p.  82,  pi.  93,  fig.  32.— ZITTEL, 
Handb.  Pal.,  vol.  1,  1879,  p.  453.— STURTZ,  N.  Jahrb.  fur  Min.,  etc., 
1886,  vol.  2,  p.  148;  Palaeontographica,  vol.  32,  1886,  p.  81;  vol.  36,  1890, 
p.  218,  pi.  27;  Verb,  naturh.  Ver.  preuss.  Eheinl.,  etc.,  vol.  50,  1893,  pp.  12, 
30.— GREGORY,  Treat.  Zool.,  vol.  3,  Echinoderma,  1900,  p.  258.— CLARKE, 
Bull.  N.  Y.  State  Mus.,  No.  121,  1908,  p.  61,  pi.  10.— SCHONDORF,  Jahrb.  nas- 
sauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  62,  1909,  p.  34. 

Generic  characters. — Disk  large;  rays  14  to  16  in  the  genotype. 
Interbrachial  actinal  areas  well  developed  but  not  over-large  for  a 
many-rayed  asterid,  either  integumentary  or  granular,  distally  con- 
cavely  cut  out  and  margined  by  several  small  inframarginals,  about 
seven  on  each  side  of  a  larger  axillary  piece. 

Madreporite  marginal,  large,  more  actinal  than  abactinal,  radi- 
ately  striate,  interbrachial,  and  situated  immediately  outside  of  the 
inframarginals.  In  the  fossils  it  appears  to  be  of  the  actinal  surface. 

Rays  long  and  slender,  protruding  beyond  the  disk  more  than 
twice  the  length  inside  the  disk.  Adambulacrals  opposite  one 
another,  with  small  lateral  spines,  prominent  and  large,  wider  than 
long,  bounding  the  rays,  and  terminating  proximally  in  pairs  of 
modified  pieces.  These  make  the  adambulacral  parts  of  the  oral 
armature.  Ambulacral  grooves  narrow,  ambulacral  ossicles  not 
seen  but  probably  arranged  opposite  one  another. 

Abactinally  the  disk  appears  to  have  a  scale-like  covering.  The 
rays  have  median  columns  of  radialia,  outside  of  which  are  stout 
columns  of  supramarginal  ossicles. 

GenoJiolotype  (type  by  monotypy). — H.  rhenanus  Roemer  (citations 
as  above).  Lower  Devonic  of  Bundenbach,  Germany.  The  above 
definition  is  based  on  the  illustrations  of  Stiirtz.  There  is  a  second 
species  in  Germany,  and  H.  filiciformis  occurs  in  England. 

50601°— Bull.  88—15 11 


160  BULLETIN   88,  UNITED   STATES   NATIONAL  MUSEUM. 

HELIANTHASTER  FILICIFORMIS  Woodward. 

Helianthaster  filiciformis  WOODWARD,  Geol.  Mag.,  dec.  2,  vol.  1,  1874,  pp.  7-10, 
fig.  on  p.  8. 

A  natural  mold  in  sandstone  measuring  about  45  mm.  in  total 
diameter.  Has  11  rays.  The  disk  "must  have  measured  10 
mm.  in  breadth.  The  arms  are  17  mm.  in  length,  and  near  their 
junction  with  the  body  are  5  mm.  broad. "  The  specimen  needs  to 
be  restudied  and  modernized. 

The  holotype  is  from  the  Upper  Devonic  at  Great  Inglebourne, 
Harberton,  South  Devon,  England,  and  is  now  in  the  collection  of 
Mr.  Champ ernowne. 

LEPBDASTERELL.A,   new   genus. 

Plate  25,  fig.  2. 
Lepidasterella  SCHUCHERT,  Fossilium  Catalogus,  Animalia,  pt.  3,  April,  1914,  p.  23. 

Much  like  Lepidaster,  but  with  24  rays  instead  of  13  as  in  that 
genus.  Rays  extending  considerably  beyond  the  disk.  The  abac- 
tinal  side  only  is  known,  but  it  shows  that  the  rays  have  slender  radial 
columns,  the  ossicles  of  which  are  disposed  alternatingly  with  the 
larger  and  more  prominent  supramarginals.  Outside  of  these  in 
some  rays  may  be  seen  the  edges  of  the  inframarginalia,  and  these 
have  well  developed  but  slender,  rather  long  spines. 

There  appear  to  be  no  ambital  areas,  as  the  inframarginals  of 
adjoining  rays  meet  and  at  their  junction  begins  the  disk.  The 
disk  appears  to  have  been  made  up  of  more  or  less  closely  adjoining 
polygonal  plates  whose  arrangement  is  not  discernible  in  the  specimen. 

The  madreporite  and  its  position  are  unknown. 

Actinal  area  unknown. 

Genoholotype  and  only  species. — L.  babcocki,  new  species. 

Remarks. — The  essential  difference  between  Lepidaster  and  Lepid- 
asterella is  that  the  former  has  13  rays  while  the  latter  has  24. 

LEPIDASTERELLA  BABCOCKI,  new  species. 

Plate  25,  fig.  2. 

Helianthaster,  new  species  CLARKE,  Fifty-ninth  Rep.  N.  Y.  State  Mus.,  1906,  p.  37, 

and  plate. 
Helianthaster  gyalum  CLARKE  (part),  Bull.  N.  Y.  State  Mus.,  No.  121,  1908,  p.  61 

(not  pis.  12,  I3=Pal3eosolaster  (?)  gyalum}. 

Description. — Rays,  24.  Length  of  best  preserved  ray  in  the 
holotype,  28  mm.  Width  of  ray  at  base,  3  mm.  Width  of  disk, 
probably  not  less  than  20  mm. 

Rays  slender  and  regularly  tapering.  Their  structure  is  only 
known  abactinally,  from  a  natural  mold  in  a  fine  sandstone.  Medi- 
ally there  is  a  narrow  but  high  column  of  radial  plates,  each  one  of 


KEVISION   OF  PALEOZOIC   STELLEROIDEA.  161 

which  alternates  with  those  of  the  supramarginal  plates.  The 
latter  are  slightly  tumid,  subquadrate  in  outline,  regular  in  size, 
but  decreasing  gradually  distally.  Outside  of  these  and  margining 
the  rays  may  be  seen  a  little  of  the  inframarginalia,  which  bear  pairs 
of  short,  slender,  and  finely  striated  spines.  There  are  from  31  to 
33  closely  adjoining  plates  in  each  one  of  the  abactinal  columns; 
there  appear  to  be  no  accessory  plates  of  any  kind  in  the  rays. 

Disk  circular  in  outline,  somewhat  tumid  and  covered  by  small 
many-sided  plates  that  originally  appear  to  have  been  closely  adjoin- 
ing. 

Remarks. — As  this  is  the  only  American  starfish  with  more  than 
five  rays,  it  is  readily  distinguished  from  all  others.  The  abactinal 
arm  structure  is  practically  that  of  Hudsonaster,  with  the  difference 
that  in  L.  labcocki  the  inframarginals  do  not  project  beyond  the 
supramarginals  and  are  therefore  not  seen  as  a  rule  from  the  dorsal 
side  in  the  natural  casts. 

Locality  and  formation. — The  holotype,  an  excellent  specimen,  was 
found  in  the  lower  part  of  the  Upper  Devonic,  near  Ithaca,  New 
York,  by  Mrs.  G.  W.  Babcock,  after  whom  the  species  is  named; 
it  is  in  her  possession.  The  writer's  attention  was  called  to  this 
interesting  specimen  by  Prof.  H.  S.  Williams  of  Cornell  University. 
Some  years  after  this  starfish  was  described  in  manuscript,  Clarke 
directed  attention  as  above  cited  to  two  others  found  in  the  Cashaqua 
shales  of  the  Portage  in  Hunt's  quarry,  at  Interlaken,  New  York. 

Cat.  No.  60627  (cast),  U.S.N.M. 

FAMILY,  unknown. 
Genus  ASTROPECTEN  Link. 

The  genus  Astropecten  is  based  upon  living  species,  and  it  is  not 
probable  that  the  Devonic  forms  are  identical. 

ASTROPECTEN  (?)  SCHLUTERI  Sturtz. 

Astropecten  schluteri  STURTZ,  Palaeontographica,  vol.  32, 1886,  p.  87,  pi.  10,  figs.  1, 
16,  2,  2a;  Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50,  1893,  pp.  51,  71. 

In  the  roofing  slates  of  the  Lower  Devonic  at  Bundenbach,  Ger- 
many. A  single  very  much  distorted  and  compressed  example  is 
the  basis  of  this  species. 

Genus  ATAXASTER  Jaekel. 
Ataxa.ster  JAEKEL,  Zeits.  geol.  Gesell.,  vol.  55, 1903,  Protokol,  p.  14  (106). 

Genoholotype  and  only  species. — A.  pygmseus  Jaekel.  Ordovicic 
(DJ,  St.  Benigna,  Bohemia. 

Description. — "A  small  asterid  whose  ambulacrals  in  the  distal 
parts  are  alternate,  but  in  the  proximal  are  opposite." 

Remarks. — The  above  is  all  that  is  known  about  Ataxaster,  and 
for  the  present  the  genus  has  no  value. 


162  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

CRYPTOZONIA  Sladen. 

Specialized  Asteroidea  without  true  marginal  plates.  In  other 
words,  there  are  no  large  and  conspicuous  marginal  plates  bordering 
the  animals,  but  in  primitive  forms  large  adambulacrals  do  margin 
the  species.  In  other  primitive  forms  more  or  less  of  the  infra- 
marginals  may  be  present,  but  if  so  they  remain  adjoining  the  adam- 
bulacrals. 

Ambulacrals  alternating  or  directly  opposite  one  another. 
Oral  armature  generally  with  the  adambulacral  elements  the  most 
conspicuous;  more  rarely  the  ambulacral  elements  are  most  promi- 
nent. 

Contains  the  following  families: 

Stenasteridae.  Schuchertiidse. 

Monasteridae.  Palasteriscidae. 

Urasterellidae.  Schcenasteridae. 

Calliasterellidae-  Palaeosolasteridae. 

Compsasteridae. 

Remarks. — This  widely  accepted  order,  which  appears  as  if  founded 
in  nature  on  a  single  grand  phylum,  probably  has  no  such  value. 
In  other  words,  asterids  without  either  one  or  both  of  the  marginal 
columns  bounding  the  animal  developed  several  times.  Therefore, 
the  absence  of  these  ossicles  is  no  indication  of  direct  phyletic 
relationship,  but  such  are  simply  cases  of  parallel  development.  As 
long  as  asterids  retain  the  primitive  characters  of  few  columns  of 
rather  strong  ossicles  and  the  adambulacral  type  of  oral  armature, 
they  are  clearly  Phanerozonia,  but  when  the  ponderous  skeleton 
breaks  up  into  a  more  flexible  one  of  small  pieces,  then  the  marginal 
and  abactinal  columns  vanish  as  such  in  the  mass  of  small  plates. 
On  the  other  hand,  ponderosity  may  even  be  retained  with  the  loss 
of  the  inframarginals  alone.  In  all  of  these  Paleozoic  forms,  the 
adambulacral  type  of  oral  armature  is  the  rule. 

Among  the  Paleozoic  "Cryptozonia"  it  seems  certain  that  at  least 
the  families  Stenasteridae,  Urasterellidae,  Schuchertiidae,  and  Palaeo- 
solasteridae  had  independent  origins  in  Phanerozonia  stocks.  The 
Urasterellidae  and  Calliasterellidae  apparently  had  a  single  origin  in 
the  Phanerozonia  subfamily  Mesopalaeasterinae  by  the  adoption  of 
marked  flexibility.  On  the  other  hand,  the  families  Stenasteridae 
and  Monasteridae  retained  rigidity  and  primitive  characters,  and 
more  probably  arose  in  the  Hudsonasteridae  through  the  loss  of  the 
iriframarginals  alone.  The  Schuchertiidae  also  had  their  origin 
directly  in  some  Phanerozonia  stock  and  one  naturally  looks  for  it 
in  forms  developing  large  interbrachial  areas  as  in  the  Palasterinidae. 
In  this  family,  however,  the  accessory  plates  are  introduced  between 
the  adambulacrals  and  inframarginals,  while  in  the  former  family  they 


KEVISION"   OF   PALEOZOIC    STELLEROIDEA.  163 

are  introduced  outside  of  the  inframarginals  and  the  entire  abactinal 
skeleton  is  broken  up  into  an  abundance  of  tiny  pieces.  Therefore,  one 
must  go  back  for  their  origin  at  least  as  far  as  the  Palaasteridse.  In 
this  case  it  was  not  primarily  flexibility  that  led  to  this  supposed 
ordinal  change,  but  it  was  due  to  increase  of  body  cavity  and  enforced 
enlarging  of  the  skeleton  in  the  interbrachial  and  ambital  areas, 
making  the  more  or  less  pentagonal  disk.  It  is  probable  that  the 
Palasteriscidas  were  their  descendants,  while  the  Schoenasteridse  may 
have  been  the  final  Paleozoic  representatives  of  the  same  phyletic  line. 
The  PalasosolasteridaB  seemingly  arose  in  the  Phanerozonia  family 
LepidasteridaB  by  the  adoption  of  a  flexible  skeleton. 

It  would,  therefore,  seem  that  the  Paleozoic  families  of  supposed 
Cryptozonia  construction  are  to  be  grouped  as  follows: 

Superfamily  Stenasteracea,  new. 

Includes  families  Stenasteridse  and  Monasteridse. 
Superfamily  Urasterellacea,  new. 

Includes  families  Urasterellidse,  Calliasterellidse,  and  Compsasteridse. 
Superfamily  Schuchertiacea,  new. 

Includes  families  Schuchertiidse,  Palasteriscidee,  and  Schcenasteridae. 
Superfamily  Palseosolasteracea,  new. 

Includes  family  Palaeosolasteridse. 

STENASTERIDSE,  new  family. 

Rigid,  small,  primitive,  five-rayed  Cryptozonia,  with  rapidly  taper- 
ing or  petaloid  rays.  Ambulacrals  few  in  number  and  opposite  in 
arrangement.  Interbrachial  areas  consisting  of  the  single  pairs  of 
large  basal  adambulacral  oral  armature  plates. 

Abactinal  skeleton  unknown,  but  in  some  forms  seemingly  integu- 
mentary. No  spines  as  yet  known.  It  is  probable  that  this  family 
will  be  referred  to  the  Auluroidea. 

Contains: 

Stenaster  Billings. 

Tetraster  Nicholson  and  Etheridge. 

Genus  STENASTER  Billings  (emend.). 
Plate  32,  fig.  1. 

Stenaster  BILLINGS,  Geol.  Surv.  Canada,  Can.  Org.  Bern.,  dec.  3,  1858,  p.  77.— 
STURTZ,  Palseontographica,  vol.  36,  1890,  p.  220.— GREGORY,  Geol.  Mag., 
dec.  4,  vol.  6,  1899,  p.  352. — SPENCER,  Mon.  Brit.  Pal.  Asterozoa,  pt.  1 
(Palseontogr.  Soc.  for  1913),  1914,  p.  22. 

Urasterella  STURTZ  (not  McCoy),  Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol. 
50,  1893,  pp.  40,  41,  56. 

Generic  characters. — Small  rigid  asterids,  the  largest  example  having 
11  =  20  mm.,  /•  =  4.5  mm.  Disk  small,  without  interbrachial  arcs. 
Rays  five,  short,  stout,  lanceolate  or  petaloid. 

Abactinal  area  devoid  of  a  preservable  skeleton.  For  this  reason 
when  this  side  is  at  hand  it  is  nearly  always  mistaken  for  the  actinal, 
so  nearly  alike  are  the  two. 


164  BULLETIN   88,  UNITED  STATES   NATIONAL  MUSEUM. 

Madreporite  unknown. 

Adambulacral  plates  with  granular  surfaces,  few  in  number,  never 
more  than  17  hi  a  column,  subquadr angular  and  thick,  greatest  width 
about  the  middle  of  the  rays,  rapidly  diminishing  in  size  distally  and 
making  the  margin  of  the  rays  and  disk.  The  great  proximal  adam- 
bulacrals  are  the  orals,  occupying  the  axils  in  pairs,  acutely  triangular, 
more  or  less  pointed,  and  terminating  orally. 

Ambulacral  plates  large,  directly  opposite  one  another  and  the 
adambulacrals  as  well,  h-  -shaped,  with  the  widest  portion  in  the  per- 
radial  center  of  the  rays;  there  are  as  many  as  16  or  17  ambulacrals 
in  a  column.  Laterally  each  plate  is  more  or  less  excavated,  both 
distally  and  proximally,  thus  leaving  very  large,  subcircular  podial 
openings. 

Spines  of  any  kind  are  so  far  unknown. 

Genoholotype  (the  first  species  and  the  one  selected  by  subsequent 
workers). — Stenaster  salteri  Billings. 

Remarks. — This  genus  has  not  had  a  good  standing,  due  largely 
to  the  fact  that  Palseaster  Hall  was  poorly  known  when  Billings 
described  Stenaster  and  further  because  he  included  two  distinct 
generic  types  in  his  genus.  A  careful  reading  of  Stenaster,  however, 
reveals  that  Billings  actually  based  his  genus  on  S.  salteri,  the  first 
form  following  the  generic  description,  and  this  selection  has  been 
followed  since.  Later  on,  McCoy  applied  the  name  Urasterella  in 
a  loose  manner  to  the  second  species  (Palseaster  pulcJiellus) ,  and 
although  it  is  a  form  of  this  genus  it  is  not  the  genotype.  Hall  (1 868) 
directed  attention  to  this  work  of  McCoy,  but  erroneously  assumed 
that  all  of  Stenaster  was  synonymous  with  Urasterella.  It  is  true, 
as  stated  by  Hall,  that  Billings's  second  species  is  congeneric  with 
Urasterella,  but  the  first  species  and  genotype  is  certainly  quite  dis- 
tinct from  McCoy's  genus.  Sttirtz  (1890)  also  points  out  the  same 
thing  and  gives  a  short  and  emended  diagnosis  of  "  Urasterella 
(Stenaster)."  In  1893  the  same  writer  applied  McCoy's  name 
Urasterella  to  Stenaster  salteri  and  made  S.  pulchellus  the  genotype 
of  Urasterella,  a  proceeding  that  violates  the  rules  of  nomenclature. 

Stenaster  as  here  restricted  differs  from  Urasterella  in  being  more 
decidedly  rigid  and  not  so  flexible  as  the  latter,  while  the  rays  are 
far  shorter  and  petaloid  in  form.  For  these  reasons,  Stenaster  has 
comparatively  few  adambulacrals  and  ambulacrals,  while  there  are 
many  more  of  these  ossicles  in  Urasterella.  Finally,  the  former 
reveals  no  abactinal  plates  or  spines  of  any  kind,  while  the  latter 
has  a  skeleton  of  small  plates  that  terminate  in  long  inarticulate 
spines  or  rods. 

Actinally  Stenaster  is  closely  related  to  Tetraster,  and  the  only 
marked  difference  is  that  the  former  has  petaloid  rays  and  more 
pronounced  adambulacral  oral  jaws. 


REVISION    OF   PALEOZOIC   STELLEROIDEA.  165 

There  would  be  no  need  to  point  out  here  the  difference  between 
such  distinct  genera  as  Stenaster  and  Palseaster  were  it  not  that 
Hall  regarded  the  former  as  a  synonym  of  the  latter.  In  Stenaster 
the  rays  are  petaloid  and  not  slender  and  regularly  tapering,  as  in 
Palseaster.  The  most  marked  distinction,  however,  is  the  fact  that 
these  two  genera  belong  to  different  orders,  for  Palseaster  has  columns 
of  iirframarginals  that  are  completely  absent  in  Stenaster.  Further, 
in  the  last-named  genus,  the  interbrachial  areas  are  made  up  each 
of  two  pairs  of  oral  armature  pieces,  while  in  Palxaster  there  are, 
distaUy  to  these,  additional  large  single  axillary  interbrachials. 

Stenaster  and  the  related  genus  Tetraster  are  very  primitive  in 
construction.  Actinally  they  are  seen  to  have  the  structure  of 
Hudsonaster  minus  the  inframarginal  columns  and  the  single  axillary 
interbrachials.  It  is  this  difference  that  makes  the  former  genera 
members  of  the  order  Cryptozonia,  while  Hudsonaster  is  the  most 
primitive  of  Phanerozonia.  Until  the  abactinal  area  is  known  ha 
Tetraster  and  Stenaster,  positive  phyletic  relationship  can  not  be 
stated,  but  in  a  number  of  specimens  of  the  latter  genus  the  evidence 
at  hand  indicates  decided  specialization  through  the  complete  removal 
of  the  heavily  plated  skeleton  of  Hudsonaster. 

Distribution. — Ordovicic  of  America.  The  following  are  the 
known  species: 

8.  salteri  Billings.     Black  River  and  Trenton. 

8.  (?)  oUusus  (Forbes).     Bala  of  Ireland  and  Wales. 

S.  (?)  coronella  (Salter) .     May  Hill  oandstone  (Siluric)  of  England. 

S.  (?)  confluens  Trautschold.     Upper  Carboniferous  of  Russia. 

STENASTER  SALTERI  Billings. 

Plate  32,  fig  1. 

Stenaster  salteri  BILLINGS,  Geol.  Surv.  Canada,  Can.  Org.  Rem.,  dec.  3,  1858, 
p.  78,  pi.  10,  figs,  la,  16.— WRIGHT,  Mon.  British  Foss.  Echinod.,  Oolitic, 
vol.  2,  pt.  1  (Palseontogr.  Soc.  for  1861),  1862,  p.  28,  fig.  15  (2)  on  p.  24. 

Original  description. — "This  species  has  rather  short,  broad  rays, 
which  are  narrower  where  they  are  attached  to  the  very  contracted 
body  than  they  are  at  about  the  center  of  their  length.  In  conse- 
quence of  this  form,  the  sides  of  the  rays  are  not  parallel,  but  a  little 
curved  outward.  As  however  only  two  specimens  have  been  col- 
lected, and  both  appear  to  be  a  little  flattened  by  vertical  pressure, 
it  may  be  that  this  leaflike  shape  of  the  rays  is  accidental  [an 
abundance  of  specimens  show  this  form  to  be  the  natural  one]. 
*  *  *  The  adambulacral  plates  are  oblong  [granular  and  from  7 
to  17  in  each  column  in  the  smallest  and  largest  examples],  and 
the  sutures  between  them  are  nearly  at  right  angles  to  the  ambu- 
lacral  grooves;  those  next  the  body  are  a  little  sloping  outward. 


166  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

Their  length  is  about  twice  their  breadth,  and  they  are  so  disposed 
that  the  greater  dimension  is  transverse  or  at  right  angles  to  the 
groove;  the  extremities  which  lie  next  to  the  grooves  are  angular, 
and  some  of  them  appear  to  have  the  contiguous  pores  partly  exca- 
vated in  them.  The  oral  plates  [adambulacrals]  are  acutely  triangu- 
lar, the  sharpest  angle  being  toward  the  mouth  [and  form  the  inter- 
brachial  areas].  The  plates  are  smooth  [the  adambulacrals  are  all 
distinctly  granular].  The  ambulacral  pores  are  very  large,  and  the 
ossicles  are  much  contracted  in  the  middle  and  greatly  expanded 
along  the  median  line  of  the  bottom  of  the  groove."  These  plates 
are  directly  opposite  one  another  and  the  adambulacrals,  and  in 
number  equal  those  of  the  latter. 

The  type-specimen  figured  by  Billings  measures:  R  =  14  mm., 
r=3.5  mm.,  R  =  4n  Width  of  a  ray  at  base  about  4  mm.,  at  about 
mid-length  5  mm.  The  largest  specimen:  K-  =  20  mm.,  r  —  4.5  mm. 

In  the  University  of  Toronto  there  is  a  specimen  that  in  every 
way,  except  one,  has  the  characters  of  Stenaster  salteri.  It  was 
found  associated  with  many  other  individuals  at  Kirkfield.  It 
differs  from  its  associates  in  having  what  appears  to  be  a  distinct 
disk,  rather  large,  with  concave  sides,  filling  in  the  spaces  between  the 
rays.  One  looks  in  vain,  however,  for  plates  or  spines,  as  the  inter- 
brachial  areas  are  nothing  more  than  an  amorphous  mass  of  cal- 
cium carbonate.  These  areas  are  very  distinct  and  stand  out  prom- 
inently, but  because  they  do  not  reveal  any  plated  or  spinif  erous  struc- 
ture the  writer  regards  them  as  false  characters,  produced  during  the 
permineralization  of  the  specimen.  This  conclusion  is  further  sup- 
ported by  the  fact  that  otherwise  the  characters  are  those  of  S. 
salteri. 

Formation  and  locality. — Three  specimens  (the  type,  No.  1398,  and 
two  fragments)  are  from  the  Trenton  limestone  at  Belleville,  Ontario, 
and  are  now  in  the  Museum  of  the  Canadian  Survey.  Another 
specimen  in  that  museum  is  on  the  same  slab  with  Petraster  rigidus 
and  has  been  labeled  Palseaster  matutina.  In  Mr.  Ulrich's  collection 
there  are  four  isolated  rays  of  this  species  obtained  by  him  from  the 
Black  River  limestone  at  Curdsville,  Kentucky.  A  further  specimen 
preserving  two  rays,  from  Government  House  Bay,  Ottawa,  was  found 
by  Mr.  Walter  R.  Billings.  In  the  Museum  of  Comparative  Zoology 
there  is  still  another  individual  which  appears  to  be  of  this  species; 
it  was  found  by  Mr.  J.  B.  Perry  at  Pant  on,  Vermont.  Finally,  an 
abundance  of  material  was  obtained  in  the  Black  River  limestones 
at  Kirkfield,  Ontario;  there  are  more  than  twenty  specimens  from 
this  locality  in  the  Walker  collection  of  the  University  of  Toronto, 
gathered  by  Mr.  Townshend. 

Cab.  No.  60628,  U.S.N.M. 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  167 

STENASTER  (?)  OBTUSUS  (Forbes). 

Asterias  primseva  SALTER  and  SOWERBY,  Quart.  Jour.  Geol.  Soc.  London,  vol. 

1,  1845,  p.  8,  20  (table)  (rumen' nudum). 
Uraster  obtusus  FORBES,  Mem.  Geol.  Surv.  Gt.  Britain,  vol.  2,  pt.  2, 1848,  p.  463; 

Mem.  Geol.  Surv.  United  Kingdom,  dec.  1,  1849,  p.  2,  pi.  1,  fig.  3. — MURCHI- 

SON,  Siluria,  1854,  p.  182,  fig.  17. 
Palxaster  obtusus  SALTER,  Ann.  Mag.  Nat.  Hist.,  ser.  2,  vol.  20,  1857,  p.  326. — 

WRIGHT,  Mon.  British  Foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1  (Paleeontogr. 

Soc.  for  1861),  1862,  p.  24.— SALTER,  Mem.  Geol.  Surv.  Gt.  Britain,  vol.  3, 

1866,  p.  289,  pi.  23,  fig.  1. 
Stenaster  (?)  obtusus  STURTZ,  N.  Jahrb.  fur  Min.,  etc.,  1886,  vol.  2,  p.  153;  Verh. 

naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50,  1893,  pp.  41,  56. 
Stenaster  obtusus  SPENCER,  Mon.  Brit.  Pal.  Asterozoa,  pt.  1  (Palseontogr.  Soc.  for 

1913),  1914,  pp.  22,  23,  31,  text  fig.  21,  pi.  1,  figs.  6,  7. 

The  little  that  is  known  of  this  species  appears  to  be  in  harmony 
with  the  characters  of  Stenaster  as  here  defined.  It  occurs  in  the 
Caradoc  beds  (Ordovicic)  at  Drumcannon,  Waterford,  Ireland,  and 
in  the  Bala  rocks  west  of  Bala  Lake  (Moel-y-Garnedd) ,  North  Wales. 

STENASTER  (?)  CORONELLA  (Salter). 

Palxaster  coronella  SALTER,  Ann.  Mag.  Nat.  Hist.,  ser.  2,  vol.  20,  1857,  p.  326.— 
WRIGHT,  Mon.  British  Foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1  (Palseontogr. 
Soc.  for  1861),  1862,  p.  25. 

Stenaster  (?)  coronella  STURTZ,  N.  Jahrb.  fur  Min.,  etc.,  1886,  vol.  2,  p.  153. 

The  description  of  this  species  is  very  short  and  almost  nothing  is 
known  of  its  characters.  It  occurs  in  the  May  Hill  sandstone  (Siluric) 
at  Gunwick  Mill,  Malvern,  England. 

STENASTER  (?)  CONFLUENS  Trautschold. 

Stenaster  conftuens  TRAUTSCHOLD,  Nouv.  Mem.  Soc.  Imp.  Nat.  Moscou,  vol.  14, 
1879,  p.  11,  pi.  2,  fig.  5.— SCHONDORF,  Palseontographica,  vol.  56,  1909,  p.  337. 

Based  on  a  fragment  of  the  distal  part  of  a  ray.  Appears  to  be 
a  crj^ptozonian.  Generic  position  unknown.  From  the  Upper  Car- 
boniferous (Moscovian)  of  Moscow,  Russia. 

Genus  TETRASTER  Nicholson  and  Etheridge  (emend.). 

Plate  33,  fig.  4. 

Tetraster  NICHOLSON  and  ETHERIDGE,  Mon.  Silurian  Foss.  Girvan  Dist.,  Ayrshire, 
fasc.  3,  1880,  p.  324,  pi.  21,  figs.  3-8  (not  figs.  1-2=  Eudsonaster  batheri,  and 
9-10==  Urasterella  girvanensis) . 

The  name  has  reference  to  the  four  columns  of  actinal  plates  of 
the  rays. 

Remarks. — The  authors  of  Tetraster  distinguished  their  genus  from 
Palseaster  on  the  ground  that  it  had  on  the  actinal  side  but  four 
columns  of  plates,  while  that  genus  as  typified  by  P.  matutinus}  now 
Hudsonaster  matutinus,  has  six.  In  this  definition  they  are  correct, 
but  they  complicated  their  good  intentions  not  only  by  referring  to 


168  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

Tetraster  another  Cryptozonia  form  (Urasterella  girvanensis,  new 
species),  but  also  by  confusing  with  their  genotype  specimens  that 
certainly  have  the  character  of  Palseaster  so  far  as  six  columns  of 
actinal  ossicles  are  concerned.  This  latter  admixture  the  writer  has 
taken  out  of  the  genotype  and  has  described  it  in  this  work  as  Hudson- 
aster  ~batheri.  The  adjusting  of  this  matter  has  been  made  possible 
through  the  kindness  of  Dr.  Bather,  who  made  for  this  work  wax 
squeezes  of  the  various  specimens.  After  seeing  these  and  the  other 
material  originally  referred  to  Tetraster  by  Nicholson  and  Etheridge, 
their  various  drawings  became  clear.  Their  figures  are  fairly  good, 
but  in  places  do  not  bring  out 'all  the  characters,  but  it  was  the 
mixture  of  three  generic  forms  under  Tetraster  that  made  it  for  a  time 
impossible  to  determine  on  what  the  genus  should  stand. 

Emended  description. — Small,  five-rayed  asterids,  E,  =  about  5  mm., 
r= about  2  mm.  Abactinal  side  unknown.  Actinally  convex  and 
in  its  general  expression  reminding  much  of  living  species  with  large 
marginals,  but  in  Tetraster  the  comparatively  massive  margining 
plates  are  adambulacralia. 

Adambulacrals  compose  the  entire  outer  actinal  areas  of  Tetraster 
and  margin  the  entire  annual.  Distally  the  pieces  are  small  and  the 
12  ossicles  of  each  column  increase  rapidly  in  size  with  the  largest 
basal  pieces  of  adjoining  columns  making  the  prominent  interbrachial 
areas.  Ambulacrally  all  are  somewhat  excavated,  stand  high  above 
the  furrow  and  each  ossicle  terminates  in  a  ridge  that  joins  those  of 
the  ambulacrals.  All  of  these  plates  are  abundantly  granular. 

Ambulacral  furrows  not  wide  but  rapidly  becoming  very  deep 
proximally,  with  excavated  adambulacral  sides.  The  columns  meet 
in  front  of  the  two  largest  interbrachial  adambulacrals.  Podial 
openings  are  large  and  issue  deeply  from  beneath  the  adambulacrals 
and  between  the  lateral  sutures  of  the  ambulacralia.  The  pieces  of 
the  ambulacral  columns  are  as  many  as  there  are  adambulacrals  and 
are  placed  directly  opposite  one  another.  Medially  the  ambulacralia 
are  elevated,  roof-like,  and  without  a  central  gutter. 

While  the  ab actinal  area  is  unknown,  it  appears  that  the  adambu- 
lacrals also  margin  this  side  of  the  animal.  The  nature  of  the  skele- 
ton inside  of  these  columns  may  be  of  small  pieces  as  hi  Urasterella, 
or,  what  seems  more  probable,  consist  of  large  radial  and  supramar- 
ginal  ossicles,  without  accessory  pieces. 

Spines  of  any  kind  are  unknown. 

Genoholotype. —  Tetraster  wyville-thomsoni  Nicholson  and  Etheridge 
as  above  emended.  T.  (?)  imbricatus  (Salter)  is  also  placed  under 
this  genus  for  the  present. 

Tetraster  as  now  defined  is  so  distinct  in  its  great  adambulacral 
development  that  it  will  not  be  confused  with  any  other  Paleozoic 
genus  except  Stenaster.  Both  genera,  so  far  as  the  actinal  area  is 


REVISION   OF  PALEOZOIC   STELLEEOIDEA.  169 

concerned,  are  closely  related.  The  differences,  however,  are  worthy 
of  generic  rank.  In  Stenaster  the  rays  are  petaloid,  with  the  adambu- 
lacrals  largest  at  the  mid-length  of  the  rays,  while  in  Tetraster  the 
rays  are  triangular,  with  the  greatest  ossicles  in  the  axils. 

At  first  the  genotype  looks  as  if  one  had  a  direct  representative  of 
living  Phanerozonia,  but  a  little  study  quickly  shows  that  the  large 
actinal  margining  plates  are  not  marginals  or  inframarginals,  but 
adambulacrals,  and  therefore  indicate  a  cryptozonian  form.  For  a 
while  it  seemed  that  these  large  plates  must  be  inframarginals,  but 
then  adambulacrals  should  be  present,  and  they  were  looked  for 
along  the  ver'tical  ambulacral  walls,  but  even  here  there  are  no 
diminutive  pieces  of  these  columns.  Among  Paleozoic  asterids  the 
writer  has  not  seen  a  form  without  adambulacrals,  and  when  there  are 
but  four  actinal  columns  it  is  always  the  inframarginals  that  are 
diminutive  or  absent. 

This  species  may  be  identical  with  T.  (?)  inibricatus  (Salter), 
which  see  for  further  remarks. 

Distribution. — Restricted  to  the  Upper  Ordovicic  at  Thraive,  Gir- 
van,  Scotland.  The  specimens  occur  as  very  sharp  natural  molds  in 
a  micaceous  sandstone,  from  which  good  wax  squeezes  can  be  made, 
revealing  all  the  skeletal  characters.  The  originals  are  in  the  collec- 
tion of  Mrs.  Robert  Gray,  Edinburgh,  Scotland. 

TETRASTER  (?)  IMBRICATUS  (Salter). 

Palseaster  imbricatus  SALTER,  Mem.  Geol    Surv.  Gt.  Britain,  vol.  3,  1866,  p. 
289,  pi.  23,  fig.  8. 

Original  description. — "P.  rigidus,  uncialis.  Radii  breves  conici, 
nee  ad  basin  valde  expansi,  subcarinati,  tuberculis  seu  jugis  obliquis 
remotiusculis  asperi. 

"Ray  conical,  its  length  about  five  lines,  its  breadth  at  base  less 
than  two  lines.  Only  two  rays  are  preserved;  these  are  convex, 
slowly  tapering,  somewhat  carinate  above  (we  do  not  see  the  lower 
side),  and  ornamented  by  tubercles  gathered  into  curved  oblique 
rows,  which  run  forward  from  the  avenues  toward  the  carina  above, 
and  are  separated  from  each  other  by  a  space  little  more  than  their 
own  breadth. 

" Locality:  Caradoc  rocks,  Llanfyllin,  Montgomeryshire  [Wales]. 
The  specimen  is  in  the  collection  of  Mr.  Prosser." 

Remarks. — As  the  writer  has  not  seen  the  holotype,  his  conclusions 
are  based  on  the  lithographic  figure,  which  adds  but  little  knowledge 
to  that  in  the  description.  As  there  are  but  two  columns  of  dorsal 
ray  plates,  it  hardly  seems  that  the  species  is  a  phanerozonian.  In 
general  it  looks  most  like  Tetraster,  but  as  the  dorsal  side  of  this 
form  is  unknown,  no  direct  comparisons  can  be  made  between  them. 
On  the  other  hand,  the  imbrication  of  the  plates,  their  large  size, 


170  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

and  completely  opposite  arrangement  suggest  that  T.  (?)  imbricatus 
may  be  an  auluroid.  Until  the  original  specimen  is  restudied  no 
definite  assignment  can  be  given  it. 

MONASTEKID^E,  new  family. 

Progressive  but  primitive  five-rayed  Cryptozonia,  with  massive 
plates,  especially  the  adambulacrals,  which  are  common  to  the  actinal 
and  abactinal  areas.  Ambulacrals  opposite.  Interbrachial  areas  con- 
sist of  a  number  of  pah's  of  adambulacrals  crowded  orally  Abacti- 
nally  the  radial  and  supramarginal  columns  consist  of  large,  closely 
adjoining  plates,  and  are  similar  to  those  of  Hudsonaster. 

Contains : 

Monaster  Etheridge. 

Genus  MONASTER  Etheridge. 

Palseaster  (Monaster}  ETHERIDGE,  jr.  (part),  Mem.  Geol.  Surv.  New  South  Wales, 

Pal.,  No.  5,  pt.  2,  1892,  pp.  70,  71. 
Etheridgaster  GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6,  1899,  p.  353  (genoholotype, 

Palxaster  clarlcd). 

Emended  description. — Animal  large,  very  stout,  with  five  thick 
petaloid  rays.  Disk  very  large,  with  marked  ray  angles. 

Abactinal  area  of  rays  with  prominent  radial,  and  supramarginal 
columns  of  large,  contiguous,  strongly  convex,  hexagonal  plates, 
densely  covered  with  small  granules  radially  arranged.  The  ossicles 
of  the  radial  columns  alternate  with  those  on  each  side  and  are  largest 
in  the  mid-length  of  the  rays,  decreasing  in  size  both  distally  and 
proximally,  but  most  rapidly  distally.  This  growth  gives  the  ray 
columns  a  decided  petaloid  form.  Outside  of  the  supramarginals  the 
animal  is  bounded  by  single  columns  of  prominent,  short,  but  very 
wide  plates,  which  are  the  abactinal  aspect  of  the  actinal  adam- 
bulacrals. These  plates  bear  numerous  spiniferous  tubercles.  The 
ossicles  of  the  axillary  disk  region  are  not  determinable.  In  the  center 
of  the  disk  there  appear  to  be  five  distinct  radials  and  a  central  disk 
plate,  and  around  these  probably  were  numerous  small  accessory 
pieces. 

Madreporite  abactinal,  large,  oval,  radially  striate,  and  situated 
near  the  axillary  margin. 

Actinally  the  rays  consist  almost  entirely  of  the  adambulacrals, 
which  are  numerous,  abundantly  tuberculate,  short,  and  very  wide. 
These  columns  increase  rapidly  in  width,  join  and  form  angular 
axillse,  and  leave  between  themselves  deep  petaloid  ambulacral 
grooves.  The  interbrachial  areas  consist  of  the  oral  extensions  of 
adjoining  columns  of  adambulacrals,  of  which  there  are  a  great  num- 
ber of  pairs,  terminating  in  the  mouth  in  five  small  pairs,  the  oral 
armature. 


KEVISION    OF   PALEOZOIC   STELLEEOIDEA.  171 

Ambulacrals  in  two  columns,  opposite,  short  but  wide,  and  about 
as  numerous  as  the  adambulacrals.  Podia!  openings  unknown. 

Genoholotype. — Palseaster  darlcei  De  Koninck.  This  is  also  the  only 
species  of  Monaster  and  occurs  in  the  "Upper  and  Lower  Marine 
series"  of  the  " Permo-Carbonif erous "  of  New  South  Wales. 

Remarks. — Mr.  Etheridge  proposed  Monaster  as  a  subgenus  of 
Palseaster,  from  which  it  differs  so  radically  as  to  give  it  easily  the 
rank  of  a  genus.  He  defines  the  group  as  follows :  In  Palseaster  "  the 
adambulacral  plates,  bordering  the  ambulacral  avenues,  are  small 
and  quadrangular,  followed  by  large  transverse  marginal  plates.  In 
our  Permo-Carboniferous  species,  on  the  contrary  the  adambulacral 
plates  are  transversely  elongated,  and  occupy  nearly  the  whole  of 
the  actinal  surface  on  each  side  the  avenues.  The  marginal  plates 
[having  reference  to  the  plates  along  the  margins  which  consist  of 
adambulacrals,  and  also  form  part  of  the  abactinal  skeleton],  in  con- 
tradistinction to  those  of  Hall's  Silurian  species,  are  here  smaller  and 
subdorsal  in  position.  The  question  now  presents  itself,  of  what  value 
in  a  classificatory  sense  is  this  character  ?  Hall  lays  particular  stress 
on  the  position  of  these  plates  on  the  actinal  side  of  Palseaster.  He 
says  it  'has  two  ranges  of  plates  on  each  side  of  the  ambulacral 
groove;  marginal  [inframarginal]  and  adambulacral  plates  on  the 
lower  side,  besides  ambulacral  or  poral  plates.  The  upper  or  dorsal 
side  has  three  or  more  ranges  of  plates/  In  the  case  of  our  specimens, 
only  one  set  of  plates,  excepting  those  of  the  ambulacral  grooves, 
are,  as  before  stated,  absolutely  actinal;  the  marginals  [same  usage 
as  before]  are  strictly  so,  or,  at  the  least  sub-dorsal.  Under  these  cir- 
cumstances, I  purpose  distinguishing  our  Australian  species  under 
the  subgeneric  name  of  Monaster  (from  the  one  or  single  row  of 
adambulacral  plates  on  each  side  of  an  ambulacral  avenue) ." 

The  original  definition  is  here  given  at  length  to  show  that  it  can 
only  apply  to  the  structure  in  Palseaster  darkei  De  Koninck,  which 
is  also  the  first  species  following  the  generic  discussion.  The  author 
in  the  same  work  describes  a  new  species  which  he  also  refers  to 
Monaster,  Palseaster  (Monaster)  giganteus,  but  its  structure  is  radi- 
cally different  and  does  not  conform  with  the  subgeneric  definition 
by  Etheridge.  Elsewhere  in  this  work  it  is  taken  as  the  genotype  of 
the  new  genus  Australaster .  Gregory  in  the  serial  above  cited  takes 
as  the  genotype  of  Monaster  the  last  named  species,  the  third  of 
Etheridge,  and  transposes  the  former  as  the  genotype  to  his  new 
genus  Eiheridgaster.  This  the  writer  holds  can  not  be  done  even 
though  Etheridge  selected  no  genotype  for  Monaster.  That  author's 
genotype,  as  the  name  implies,  refers  to  a  species  with  but  a  single 
column  of  plates  on  each  side  of  the  ambulacrum.  The  species  selected 
by  a  subsequent  author  should  have  the  structure  implied  in  the 


172  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

original  generic  definition  and  when  none  actually  applies,  then  the 
first  species  following  the  generic  diagnosis.  That  Gregory  fully 
appreciated  the  structural  difference  between  Palseaster  clarkei  and 
P.  (M.)  giganteus  is  shown  in  his  reference  of  the  former  to  the  order 
Phanerozonia  and  the  latter  to  the  Cryptozonia.  Our  disagreement 
is  not  as  to  structure  but  in  the  interpretation  of  the  rules  of  nomen- 
clature. Under  these  circumstances  P.  clarkei  is  retained  as  the  geno- 
type of  Monaster,  since  it  appears  that  P.  giganteus  has  both  infra- 
marginals  and  adambulacrals  on  the  actinal  side,  a  structure  quite 
different  from  that  described  for  and  present  in  Monaster  Etheridge. 

After  the  above  was  written  in  1900,  the  writer  explained  by  letter 
to  Professor  Etheridge  what  Gregory  had  done.  Etheridge  replied 
under  date  of  June  6,  1900:  "The  laws  of  zoological  nomenclature 
should  have  guided  Doctor  Gregory  to  have  selected  the  first  species 
described,  as  the  subgeneric  type,  in  the  absence  of  any  statement  to 
the  contrary  on  my  part.  As  you  say,  Eiheridgaster  is  certainly  a 
synonym  of  Monaster." 

Monaster  is  most  like  Hudsonaster.  It  retains  the  primitive  pon- 
derous skeleton  of  the  latter,  but  curiously  has  lost  the  inframarginal 
columns  of  ossicles,  although  the  supramarginals  are  present. 

MONASTER  CLARKEI  (De  Koninck). 

Palseaster  clarkei  DE  KONINCK,  Mem.  Soc.  roy.  Sciences,  Liege,  ser.  2,  vol.  2,  1877, 
p.  166,  pi.  7,  figs.  6,  6a;  (David),  Mem.  Geol.  Surv.  New  South  Wales,  Pal. 
No.  6,  1898,  p.  127,  pi.  7,  figs.  6a,  66. 

Palseaster  (Monaster)  clarkei  ETHERIDGE,  jr.,  Mem.  Geol.  Surv.  New  South  Wales, 
Pal.  No.  5,  pt.  2,  1892,  p.  71,  pi.  14,  figs.  1,  2;  pi.  15,  fig.  4. 

Etheridgaster  clarkei  GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6,  1899,  p.  353. 

Of  this  species  three  natural  molds  have  been  found  in  the  "Upper 
Marine "  and  "Lower  Marine'7  series  (Carboniferous)  of  Northum- 
berland County,  New  South  Wales.  The  holotype  in  the  Clarke 
collection  was  destroyed  by  fire. 

The  species  attained  a  large  size,  the  rays  from  the  center  of  the 
disk  to  their  extremities  are  not  less  than  5  cm.,  and  in  another 
specimen  are  6.5  cm. 

URASTERELLID^E,  new  family. 

Txniasteridse  GREGORY  (part),  Geol.  Mag.,  dec.  4,  vol.  6,  1899,  p.  351  (includes 

Tseniaster,  fStenaster,  Urasterella,  Protasteracanthion,  Salteraster). 
Roemerasterinx  GREGORY,  Treat.  Zool.,  vol.  3,  Echinoderma,  1900,  p.  255. 

Specialized  Cryptozonia,  with  alternate  ambulacra,  and  with  adam- 
bulacral  type  of  oral  armature.  Rays  five,  rather  flexible,  long  and 
gently  tapering,  proximally  united  without  forming  interbrachial 
areas.  No  inframarginals  discernible  as  such  at  maturity,  the  actinal 
margin  being  occupied  by  well-developed  adambulacrals.  Abactinal 
area  composed  of  numerous  small  plates  arranged  in  columns  and 


KEVISION   OF   PALEOZOIC    STELLEKOIDEA.  173 

quincunx.  The  radial  and  supramarginal  columns  may  be  dis- 
cernible in  somewhat  larger  plates.  Adambulacrals  many,  like  coins 
set  on  edge.  * 


Contains: 

Urasterella  McCoy 


Genus  URASTERELLA  McCoy  (emend.). 
Plates  27  to  30. 

Urasterella  McCoY,  British  Pal.  FOBS.,  1851,  p.  59  (not  defined).— HALL,  Twentieth 
Kept.  N.  Y.  State  Cab.  Nat.  Hist.,  1868,  p.  289;  rev.  ed.,  1868=1870,  p.  332.— 
McCoY,  Geol.  Surv.  Victoria,  dec.  1,  1874,  p.  42.— ZITTEL,  Handb.  Pal., 
vol.  1,  1879,  p.  453.— STURTZ,  N.  Jahrb.  fur  Min.,  etc.,  1886,  vol.  2,  p.  152; 
Palseontographica,  vol.  36, 1890,  p.  219. — GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6, 
1899,  p.  352. 

Stenaster  BILLINGS  (part),  Geol.  Surv.  Canada,  Can.  Org.  Rem.,  dec.  3,  1858, 
p.  77.— STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50,  1893, 
pp.  40,  56. 

Eoemeraster  STURTZ,  Palaeontographica,  vol.  32, 1886,  p.  85  (genoholotype,  Asterias 
asperula  Roemer);  vol.  36,  1890,  p.  220;  Verh.  naturh.  Ver.  preuss.  Rheinl., 
etc.,  vol.  50,  1893,  pp.  52,  73. 

Protasteracanthion  STURTZ,  Palseontographica,  vol.  32,  1886,  p.  90  (genoholotype, 
P.  primus  Stiirtz= Asterias  asperula  Roemer);  Verh.  naturh.  Ver.  preuss. 
Rheinl.,  etc.,  vol.  50,  1893,  pp.  54,  75. 

Palasteracanthion  STURTZ,  N.  Jahrb.  fur  Min.,  etc.,  1886,  vol.  2,  p.  153  (genoholo- 
type, "A,  primus  "= Asterias  asperula  Roemer). — STURTZ,  Verh.  naturh.  Ver. 
preuss.  Rheinl.,  etc.,  vol.  50,  1893,  p.  75. 

Salteraster  STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50,  1893,  pp. 
43,  60  (genoholotype,  Palseaster  asperrima  oalter). 

fEoactis  SPENCER,  Mon.  Brit.  Pal.  Asterozoa,  pt.  1  (Palseontogr.  Soc.  for  1913), 
1914,  p.  30  (genoholotype,  E.  simplex  Spencer=?  Urasterdla  girvanensis). 

Generic  characters. — Disk  very  small,  without  interbrachial  arcs. 
Rays  five,  very  long  and  slender  at  maturity,  but  shorter  and  rapidly 
tapering  when  immature. 

Abactinal  side  with  very  numerous  small  stellate  plates,  all  of 
which,  excepting  one  or  three  medial  columns,  are  drawn  out  into 
more  or  less  long,  blunt,  stout,  erect,  nonarticulating  rods.  The  disk 
is  occupied  by  a  central  plate  and  a  first  ring  with  five  plates,  which 
in  some  species  are  seen  to  be  the  basal  radial  plates,  followed  by  a 
second  ring  with  1 5  plates.  Five  of  the  latter  are  the  second  proximal 
radial  plates,  and  10,  basal  plates  of  the  supramarginal  columns. 
Between  the  central  plate  and  the  first  ring  there  may  be  inserted  a 
few  accessory,  much  smaller  pieces.  These  disk  ossicles  may  remain 
more  prominent  throughout  life  or  may  have  the  size  of  the  other 
abactinal  plates,  in  which  case  their  arrangement  is  not  plainly  made 
out.  In  the  center  of  the  ray  the  adial  column  may  be  the  more 
conspicuous  throughout  life  or  it  may  be  more  or  less  completely 
suppressed  when  the  supramarginals  adjoin  and  these  may  then 


174  BULLETIN   88,  UNITED   STATES   NATIONAL   MUSEUM. 

be  the  more  prominent  columns.  Or  the  entire  abactinal  area  of  the 
rays  may  be  composed  of  ossicles  arranged  in  columns  and  in 
quincunx  when  the  plates  are  of  nearly  equal  size.  The  number  of 
columns  varies  with  age  and  in  different  species,  the  greatest  number 
observed  being  13  at  the  base  of  a  ray. 

Ambital  plates  often  not  readily  distinguishable  at  maturity  from 
the  radial  and  supramarginal  columns.  The  growing  distal  tips  of 
the  rays  of  Urasterella  have  no  ambital  plates,  but  shortly  after  their 
introduction  they  begin  to  develop  the  rodlike  extension  so  charac- 
teristic of  this  genus.  Of  these  columns  there  may  be  as  many  as 
four  at  the  base  of  a  ray  on  each  side  of  the  supramarginals. 

Inframarginals,  as  such,  usually  not  distinguishable  at  maturity 
from  the  ambital  plates.  Their  position  is  rather  abactinal  than 
actinal.  At  the  distal  end  of  rays,  however,  these  plates  lose  their 
ambital  character,  passing  over  somewhat  to  the  actinal  side,  and 
closely  adjoin  the  adambulacrals.  In  the  young  of  U.  ulrichi  the 
inframarginals  are  well  developed  in  the  axillary  regions  and  here 
there  is  also  a  single  interbrachial  marginal  plate.  More  dis tally, 
however,  the  inframarginals  have  the  character  of  the  ambital  plates. 
In  none  of  the  mature  specimens  have  been  seen  well-developed  or 
larger  axillary  inframarginals  or  interbrachial  marginal  plates.  In 
U.  asperula  the  axils  have  actinally  single  plates  which  may  be 
remnant  inframarginals. 

Madreporite  abactinal,  of  medium  size,  slightly  convex,  depressed 
and  granules triate. 

Adambulacral  plates  very  numerous,  coin-shaped,  and  arranged  on 
edge  with  the  actinal  surface  pustulose.  Each  plate  on  its  actinal 
surface  bears  two  or  three  short,  thick  spines,  and  on  its  ambulacral 
side  there  is  another  similar  spine.  Along  the  outer  edge  of  these 
plates  toward  the  abactinal  side  there  is  another  row  of  spines,  in 
pairs,  which  are  long  and  slender,  flat,  and  longitudinally  grooved 
on  two  sides.  The  adambulacral  columns  terminate  in  small  tri- 
angular plates  of  the  oral  armature.  In  the  young  of  U.  ulrichi  five 
very  stout,  short,  pointed  spines  (tori)  are  inserted  inside  of  the  plates 
of  the  oral  armature. 

Ambulacral  columns  with  the  ossicles  generally  slightly  alternating, 
but  they  may  also  be  opposed,  one  plate  to  each  adambulacral  piece, 
more  or  less  wedge-  or  club-shaped,  and  those  of  each  column  par- 
tially overlapping.  Medially  the  columns  loosely  adjoin.  Each 
plate  is  excavated  laterally,  along  the  proximal  edge,  leaving  a  more 
or  less  long,  slender  podial  opening  between  adjoining  plates. 

Genoholotype. —  Uraster  ruihveni  Forbes.  The  above  diagnosis, 
however,  is  based  on  Stenaster  grandis  Meek,  a  form  thought  to  be 
in  generic  harmony  with  the  genotype. 


KEVISION   OF   PALEOZOIC    STELLEKOIDEA.  175 

Distribution. — The  species  occur  in  North  America  and  Europe  and 
range  from  the  Ordovicic  to  the  Upper  Carboniferous.  The  following 
are  the  known  species: 

U.  pulcJiella  (Billings).     Trenton. 

U.  grandis  (Meek).     Richmond. 

U.  fiuxleyi  (Billings).      ?Chazy. 

U.  ulrichi,  new  species.     Lowville. 

U.  girvanensis,  new  species.     Upper  Ordovicic  of  Scotland. 

U.  (?)  asperrima  (Salter).     Bala  of  Wales. 

U.  (?)  constellata  (Thorent).     Siluric  of  France. 

U.  ruthveni  (Forbes).     Ludlow  of  England. 

U.  Jiirudo  (Forbes).     Ludlow  of  England. 

U.  selwyni  McCoy.     Siluric  of  Australia. 

U.  asperula  (Roemer).     Lower  Devonic  of  Germany. 

U.}  new  species.     Ithaca  beds.     Upper  Devonic. 

U.  montana  (Stschurowsky).     Upper  Carboniferous  of  Moscow, 

Russia. 

Remarks.-— McCoy  in  suggesting  the  name  Urasterella  did  it  in  the 
following  words: 

11  Before  I  was  aware  Prof.  E.  Forbes  had  described  them  it  seemed 
to  me  that  the  U.  [raster]  RutJiveni  and  U.  Hirudo,  as  well  the  similar 
American  species,  might  be  easily  separated  from  the  great  star- 
fishes forming  the  recent  genus  Uraster,  by  their  small  size  and  much 
more  simple  skeletons,  and  I  had  named  the  genus  Urasterella  in  my 
manuscript." 

This  is  all  that  McCoy  did  to  establish  the  genus  Urasterella, 
abandoning  his  manuscript  definition  on  learning  that  Forbes  had 
described  the  species  as  those  of  Uraster.  Salter1  in  1857  paid  no 
attention  to  this  name,  although  he  was  the  first  to  recognize  and 
define  Palasterina,  which  McCoy  proposed  at  the  same  time  and  in 
the  same  manner.  It  seems  that  Hall  (1868,  p.  332)  was  the  first 
to  revive  the  name  Urasterella  and  regarded  Billings's  Stenaster  as  a 
synonym  by  taking  his  second  species,  8.  pulchella,  as  the  genotype. 
Hall's  remarks  are  as  follows:  "Mr.  Salter,  apparently  overlooking 
my  description  of  Pal&aster  niagarensis,  has  placed  both  the  above- 
cited  European  species  [  Uraster  rutTiveni  and  U.  Jiirudo]  under  Palae- 
aster,  as  defined  by  himself;  but  as  it  has  been  shown  that  this  genus 
has  two  ranges  of  plates  on  each  side  of  the  ambulacral  groove,  these 
forms  can  not  with  propriety  be  arranged  with  typical  Palseasters. 

"  There  was  the  same  reason  for  adopting  the  generic  term  Uras- 
terella as  for  adopting  Palasterina,  both  of  which  were  proposed  by 
McCoy  at  the  same  time,  and  the  typical  forms  of  each  were  specified. 
Mr.  Salter  has  for  some  reason  recognized  the  genus  Pabea,ster  pro- 

iAnn.  Mag.  Nat.  Hist.,  ser.  2,  vol.  20, 1857,  p.  326. 
50601°— Bull.  88 — 15 12 


176  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

posed  by  me  a  little  earlier,  but  probably  published  after  that  of  McCoy; 
and  has  given  the  two  species  of  Urasterella  to  that  genus.  Now 
that  there  seems  no  reason  for  continuing  them  under  that  generic 
term,  they  should  be  restored  to  their  proper  position  as  indicated 
above.  The  two  species  of  Forbes  must  either  be  placed  under 
Urasterella  as  proposed  by  McCoy,  or  fall  under  the  later  genus 
Stenaster  of  Billings.  Were  the  latter  genus  of  my  own  proposing 
I  should  nevertheless  return  to  Urasterella,  and  I  have  no  doubt 
that  Mr.  Billings  will  accord  with  this  view." 

Palseaster  pulcJiellus  is  a  true  Urasterella,  but  this  does  not  make 
the  genus  Stenaster  a  synonym  of  Urasterella,  since  S.  salteri  Billings 
has  quite  another  structure  and  is  here  accepted  as  the  genotype  of 
Stenaster. 

Meek1  also  recognizes  McCoy's  name,  but  because  of  certain  pecul- 
iarities in  S.  salteri,  which  he  recognizes  as  the  genotype,  and  also 
since  he  had  not  seen  the  dorsal  side  of  McCoy's  S.  grandis,  he  prefers 
to  retain  Stenaster  for  the  latter. 

McCoy  returned  to  his  genus  in  1874,  after  going  to  Australia,  and 
described  a  new  form,  U.  selwyni.  It  is  important  to  quote  here 
his  remarks : 

" Genus  Urasterella  (McCoy )=  Stenaster  (Billings). 

"Gen.  Char.:  Small  starfishes,  with  five  moderate  rays,  narrowed 
at  the  base,  and  without  disk.  Ambulacral  grooves  narrow,  bor- 
dered on  the  under  side,  with  only  one  row  of  large  (adambulacral) 
plates;  no  marginal  plates.  Upper  surface  with  numerous  rows  of 
small  tubercular  plates.  Confined  to  Silurian  rocks. 

"The  late  Mr.  Salter  and  Mr.  Billings  refer  the  starfishes  of  this 
type  to  the  subsequently  published  genus  Pateaster  of  Hall;  but, 
as  Prof.  Hall  objects  that  his  genus  Palseaster  has  ambulacral,  adam- 
bulacral, and  marginal  plates,  and  the  types  of  my  genus  U.  ruthveni 
and  U.  Jiirudo  of  the  English  Ludlow  rock,  like  our  Australian  species 
and  the  American  Pals&aster  or  Stenaster  pulchella,  have  only  one  row 
of  plates  on  each  side  of  the  ambulacral  groove,  I  return  to  the  use 
of  my  old  generic  name." 

Zittel2  says  that  Stenaster  is  a  synonym  for  Urasterella  and  defines 
the  latter  genus.  Stiirtz3  points  out  the  errors  in  the  diagnosis  of 
Billings  and  that  of  Zittel,  redefines  the  genus,  and  correctly  states 
that  Stenaster  Billings  contains  species  of  two  genera,  that  is,  Sten- 
aster salteri,  the  genotype  of  Stenaster,  and  S.  pulchella,  which  he  refers 
to  Urasterella.  In  this  way  the  genus  Urasterella  has  come  to  be 
recognized. 

The  figure  and  description  of  Uraster  ruthveni  given  by  Forbes* 
appears  to  be  of  a  species  generically  identical  with  the  American 

1  Pal.  Ohio,  vol.  1, 1873,  p.  67.  s  Palseontographica,  vol.  36, 1890,  p.  219. 

2  Handb.  Pal.,  vol.  1, 1879,  p.  453.          *  British  Org.  Rem.,  dec.  1, 1849,  p.  1,  pi.  1,  fig.  1 . 


REVISION    OF   PALEOZOIC    STELLEROIDEA.  177 

Stenaster  pulchellus  Billings  and  this  is  the  general  consensus  of  opinion. 
The  writer  unfortunately  had  no  material  of  the  genotype  of  Uras- 
terella  for  study.  However,  since  U.  grandis  is  closely  related  to  U. 
pulchella  and  shows  so  much  more  detail,  it  is  here  accepted  as  the 
genotype  for  the  time  being. 

Professor  Hall  (1870)  wrote:  " In  Stenaster  =  Urasterella,  however, 
we  have  the  absence  of  adambulacral  plates."  This  is  nevertheless 
not  the  case,  for  the  corn-shaped  marginal  series  in  S.  pulchellus  are 
the  ambulacral  plates,  since  weU-developed  inframarginal  plates,  as 
in  Palseaster,  are  absent  in  mature  Urasterella.  The  inframarginals 
are,  however,  seen  to  be  present  in  U.  pulchella  or  in  the  distal  ends 
of  the  rays  in  other  species,  though  proximally  they  are  so  modified 
as  not  to  be  readily  distinguishable  from  the  ambital  plates.  In  the 
axils  of  the  young  of  U.  ulrichi  the  inframarginals  are  well  developed, 
along  with  single  interbrachial  marginal  plates,  but  in  mature  speci- 
mens of  other  species  none  have  been  seen. 

Of  Roemeraster  the  writer  has  seen  three  excellent  specimens  skil- 
fully prepared  by  Sttirtz  which  clearly  show  that  this  genus  has  the 
generic  structure  of  Urasterella.  Stiirtz 1  describes  this  genus  as 
having  "strong  marginal  plates"  inside  of  the  "small,  cornered  adam- 
bulacrals."  Our  specimens  do  not  show  such  plates,  and  if  present 
they  can  not  be  adambulacrals.  This  fact  can  be  demonstrated 
in  a  well-preserved  distal  end  of  a  ray,  where  two  columns  are  present 
on  each  side  of  the  ambulacrals.  The  innermost  column  of  closely 
adjoining  plates  increase  in  size,  retain  iheir  position  beside  the  ambu- 
lacrals, and  become  the  most  prominent  of  the  entire  animal,  while 
the  outermost  column  soon  change  in  aspect,  the  plates  become 
separated  and  assume  the  characters  of  the  ambital  pieces.  This 
is  likewise  true  in  the  young  of  U.  ulrichi  where  the  axillary  areas 
also  have  distinct  interbrachial  marginal  and  two  larger  proximal 
inframarginal  plates.  Passing  distally,  the  latter  also  soon  change 
then-  form,  are  separated  one  from  another  and  are  not  distinguish- 
able from  the  ambital  plates.  Stiirtz  further  describes  and  figures 
five  interbrachial  ossicles  in  mature  Urasterella  asperula  which  are 
also  well  developed  in  the  young  of  U.  ulrichi.  Urasterella  is  an 
easily  recognized  genus  and  the  triangular  ambital  plates  drawn  out 
into  short  blunt  erect  rods  are  peculiar  to  it,  a  character  again  re- 
peated in  Roemeraster.  Under  these  circumstances  the  latter  appears 
to  be  indistinguishable  from  Urasterella.  For  other  remarks  see 
U.  asperula.  On  the  other  hand,  Gregory  regards  Roemeraster  as  a 
good  genus  and  places  it  erroneously  among  the  ophiuridlike  asterids 
in  the  family  Tseniasteridse. 

i  Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50, 1893,  p.  52. 


178  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

In  regard  to  Protasteracanthion  Stiirtz,  see  remarks  under  Uras- 
terella  asperula,  and  for  Salteraster  Sturtz  see  U.  asperrima. 

Urasterella  differs  from  Stenaster  as  redefined  in  this  work  in  having 
long,  slender,  flexible  rays  which  are  never  short  and  petaloid  as  in 
the  latter  genus.  Again,  the  adambulacral  pieces  of  Urasterella  are 
very  numerous,  thin,  and  coin-shaped,  while  in  Stenaster  they  are  few 
in  number  and  comparatively  thick;  the  ambulacral  plates  are 
wholly  different. 

The  long,  slender  and  flexible  rays,  the  apparent  absence  of  in- 
framarginal  columns,  and  the  absence  of  distinct  interbrachial 
plates  (these  are  not  the  same  as  the  single  axillary  pieces  seen  in 
U.  asperula)  at  maturity  readily  distinguish  this  genus  from  all  other 
Paleozoic  genera. 

For  the  origin  of  Urasterella  see  U.  ulrichi. 

Eoactis. — After  this  book  was  completed  appeared  the  work  of 
Spencer,  with  the  new  genus  Eoactis.  It  is  probable  that  the  genus 
is  good  and  can  be  distinguished  from  Urasterella,  but  the  necessary 
comparisons  can  not  now  be  made. 

URASTERELLA  PULCHELLA  (Billings). 

Plate  28,  figs.  3,  4;  plate  30,  fig.  5. 

Palseaster  pulchellus  BILLINGS,  Geol.  Surv.  Canada,  Rep.  Progress  for  1853-1856, 

1857,  p.  292. 
Stenaster  pulchellus  BILLINGS,  Geol.  Surv.  Canada,  Can.  Org.  Hem.,  dec.  3,  1858, 

p.  79,  pi.  10,  fig.  2.— WRIGHT,  Mon.  British  Foss.  Echinod.,  Oolitic,  vol.  2, 

pt.  1  (Palaeontogr.  Soc.  for  1861),  1862,  p.  28. 
Urasterella  (Stenaster)  pulchellus  HALL,  Twentieth  Rep.  N.  Y.  State  Cab.  Nat. 

Hist.,  1868,  p.  289;  rev.  ed.,  1868=1870,  p.  332. 

The  largest  specimen  from  Middleville,  New  York  (Hall  collection), 
measures:  11  =  52  mm.,  r=»ll  mm.,  R  =  4.8r.  An  individual  of  the 
usual  size  from  Trenton  Falls,  New  York  (Mus.  Comp.  Zool.,  No.  31), 
measures:  R  =  30  mm.,  r  =  4.  mm.,  R  =  7.2r.  One  from  Ottawa 
(Geol.  Surv.  Canada  collection)  measures:  R  =  25  mm.,  r  =  4  mm., 
R  =  6.1r.  The  smallest  specimen  seen  (Mus.  Comp.  Zool.,  No.  36) 
measures:  R  =  7  mm.,  r  =  1.5  mm.,  R  =  4.7r.  Width  of  rays  at 
base  in  mature  examples  from  4.5  mm.  to  7  mm. 

Original  description. — " Diameter,  2J  inches;  rays  subcylindrical,  2J 
lines  in  width  at  the  base,  with  a  length  of  1  inch;  disk  3J  lines  in 
diameter;  grooves  narrow,  bordered  throughout  by  narrow  oblong 
plates,  nine  in  the  length  of  two  lines;  the  length  of  these  plates  in  a 
direction  transverse  to  the  rays  is  about  1  line;  near  the  disk  there 
appears  to  be  but  one  row  of  marginal  plates." 

Formation  and  locality. — Restricted  to  the  Trenton  limestone. 
Most  abundant  at  Trenton  Falls,  New  York.  From  this  locality 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  179 

there  are  two  specimens  in  the  New  York  State  Museum  and  six 
in  the  Museum  of  Comparative  Zoology,  Harvard  University,  col- 
lected by  Dr.  C.  D.  Walcott  (Nos.  31-36).  The  American  Museum 
of  Natural  History  has  one  specimen  from  Canajoharie,  New  York 
(No.  660) ;  in  the  Hall  collection,  Albany,  there  is  a  specimen  from 
Middle viUe,  New  York.  At  Hull,  Canada,  Mr.  W.  R.  Billings  col- 
lected two  specimens;  the  type  and  another  specimen  were  found 
by  E.  Billings  at  Ottawa,  Canada;  these  are  now  in  the  Museum  of 
the  Geological  Survey  of  Canada  at  Ottawa. 

Remarks. — This  graceful  species  has  the  essential  structure  of 
U.  grandis  and  will  therefore  not  require  a  detailed  description. 
U.  pulchella  is  from  a  lower  geological  horizon,  is  probably  the  an- 
cestor of  U.  grandis  and  has  far  less  numerous  abactinal  plates, 
which  on  the  disk  reveal  a  primitive  arrangement  reminding  one  of 
Hudsonaster.  In  the  center  of  the  disk  there  is  a  single  plate  around 
which  is  a  first  ring  of  5  basal  radial  plates  followed  by  another  with 
15  plates.  The  plates  of  the  second  ring  are  a  little  more  conspicu- 
ous than  any  other  abactinal  plates  and  are  disposed  as  follows: 
Five  are  radial  in  position  and  are  the  second  basal  plates  of  the 
5  radial  columns,  while  the  other  10  are  disposed  interradially  in 
pairs  immediately  on  each  side  of  the  second  basal  radials.  The 
plates  interradial  in  position  are  the  basals  of  the  supramarginal 
columns.  Between  the  central  ossicle  and  first  ring  there  appear 
to  be  a  few  small  accessory  plates. 

The  arrangement  of  the  disk  pieces  above  described  is  plainly 
preserved  in  a  very  young  example  (No.  36,  MILS.  Comp.  Zool.). 
The  radial  columns  remain  the  most  prominent  while  the  supra- 
marginals  a  little  distally  from  the  base  of  the  rays  are  not  readily 
distinguishable  from  the  other  columns.  Here  and  there  an  accessory 
piece  may  be  inserted  between  the  radials  and  supramarginals  but 
the  greater  width  of  the  rays  is  attained  by  increasing  the  size  of 
these  columns  and  by  the  introduction  of  ambital  columns  outside 
of  the  supramarginals.  In  a  mature  ray  on  each  side  of  the  radials 
proximally,  there  appear  to  be  not  more  than  four  columns  of  plates 
but  it  is  possible  that  a  few  pieces  of  a  fifth  column  may  be  developed. 
The  form  and  spinosity  of  the  abactinal  plates  is  as  in  U.  grandis, 
except  that  the  nonarticulating  spines  are  less  long  in  U.  pulchella. 

Inframarginal  columns  at  first  view  do  not  appear  to  be  present 
but  a  careful  examination  near  the  distal  end  of  a  ray  reveals  two 
columns  of  nearly  equal-sized  plates  on  each  side  of  the  ambulacral 
furrow.  Here  these  plates  closely  adjoin,  the  adambulacrals  are 
elongate  subquadrangular  and  the  inframarginals  quadrangular  in 
shape.  Proceeding  proximally  the  former  become  more  prominent 
and  wider  but  remain  throughout  closely  adjoining.  The  inframar- 
ginals, however,  gradually  pass  over  to  the  abactinal  side  although 


180  BULLETIN  88,  UNITED  STATES  NATIONAL  MUSEUM. 

they  remain  beside  the  adambulacrals,  become  more  and  more 
spinose,  longer  than  wide,  and  eventually  stellate  in  form  and  then 
are  inseparable  from  the  abactinal  plates.  There  are  about  42  adam- 
bulacrals in  each  column. 

U.  pulchella  is  readily  distinguished  from  U.  ulricJii  and  U.  grandis 
in  being  smaller,  with  more  slender  and  graceful  rays,  and  in  its  fewer 
columns  of  plates.  From  U.  Jiuxleyi  it  is  distinguished  by  the  less 
convex  rays  and  the  far  smaller  number  of  plates. 

Cat.  No.  60610,  U.S.N.M. 

URASTERELLA  GRANDIS  (Meek). 

Plate  27,  figs.  6-8;  plate  28,  figs.  1,  2;  plate  30,  figs.  1-4. 

Stenaster  grandis  MEEK,  Amer.  Journ.  Sci.,  ser.  3,  vol.  3,  1872,  p.  258;  Geol.  Surv. 

Ohio,  Pal.,  vol.  1, 1873,  p.  66,  pi.  3  bis,  figs.  7a-7c.— MILLER,  N.  Amer.  Geol. 

Pal.,  1889,  p.  283,  fig.  432. 

Urasterella  grandis  MEEK,  Geol.  Surv.  Ohio,  Pal.,  vol.  1,  1873,  p.  67. 
Palseaster  harrisi  MILLER,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  2,  1879,  p.  117, 

pi.  10,  figs.  2,  2<z. 

Original  description. — "Attaining  a  very  large  size,  with  the  body 
or  disk  comparatively  small,  or  only  of  the  breadth  of  the  united 
inner  ends  of  the  five  rays.  Rays  long,  slender,  gradually  tapering, 
and  very  flexible,  widest  at  their  immediate  connection  with  the 
body,  where  they  seem  to  be  more  or  less  depressed,  but  becoming 
more  nearly  terete  farther  out.  Dorsal  side  of  body  and  arms  com- 
posed of  numerous  subtrigonal  pieces  that  rise  into  pointed  tubercles, 
or  sometimes  assume  almost  the  character  of  short  spinules,  and 
are  arranged  hi  quincunx,  so  as  to  form  about  eight  rows  near  the 
middle  of  the  rays;  those  of  the  outer  two  rows  being  a  little  larger 
than  the  others.  Dorsal  pores  apparently  rather  large,  and  passing 
through  between  the  concave  sides  of  contiguous  pieces.  Ventral 
side  of  body  unknown.  That  of  the  rays  composed  of  the  usual  single 
row  of  transverse  adambulacral  pieces  on  each  side  of  the  well 
defined,  rather  deep,  and  moderately  wide  ambulacral  furrows. 
Adambulacral  pieces  rather  more  than  twice  as  long  as  wide,  with 
their  longer  diameters  at  right  angles  to  the  ambulacral  furrows, 
and  rounding  over  from  end  to  end  so  as  to  be  most  prominent  in 
the  middle;  while  they  do  not  connect  with  each  other  by  flat  sides, 
but  have  little  projecting  processes,  and  corresponding  sinuses, 
apparently  for  the  purpose  of  imparting  greater  flexibility  to  the 
rays." 

Emended  description. — The  largest  specimen  being  doubled  over 
actinally  does  not  permit  of  exact  measurements,  but  it  is,  as  near 
as  can  be  determined,  as  follows:  R  =  93  mm.,  r  =  9  mm.,  R  =  10.3r. 
Another  specimen  spread  flatly  measures:  11  =  49  mm.,  r=6.5  mm., 
11  =  7.67-.  The  smallest  specimen  (holotype  of  Palseaster  Jiarrisi] 


REVISION   OF   PALEOZOIC   STELLEEOIDEA.  181 

measures:  R  =  10  mm.,  r  =  2.5  mm.,  R  =  4r.  Width  of  rays  at  base 
in  mature  examples  from  7  mm.  to  8.5  mm. 

Rays  at  maturity  very  long,  depressed  subcylindrical  in  outline, 
slender  and  tapering  slowly.  Disk  very  small,  formed  by  the  united 
inner  ends  of  the  rays. 

Abactinal  area  reticular,  consisting  of  very  numerous,  highly 
conical,  stellate  plates,  the  radial  columns  and  the  plates  of  the  disk 
most  prominent,  while  the  other  ray  plates  (supramarginal  and 
ambit al)  are  smaller  and  irregularly  triangular  in  form.  All  plates 
are  more  or  less  drawn  out  into  stout,  blunt,  nonarticulating  spines 
which  are  best  preserved  along  the  sides  of  the  rays.  On  the  disk 
the  ossicles  are  arranged  in  a  few  concentric  rows  while  on  the  rays 
they  are  in  columns  and  in  quincunx.  Near  the  base  of  a  ray  in  the 
largest  specimen  there  are  about  13  columns,  diminishing  to  about 
4  at  the  distal  ends. 

Madreporite  of  medium  size,  lobate,  radially  crenulostriate,  situ- 
ated between  two  adjoining  rays  and  about  midway  between  the 
margin  and  center  of  disk. 

Adambulacral  plates  slightly  overlapping  the  ambulacral  columns, 
diminishing  in  size  distally,  coin-shaped,  arranged  on  edge,  and  vary- 
ing in  different  specimens  from  60  to  110  in  each  range.  In  the 
youngest  known  example  there  are  about  20  plates  in  a  column. 
Each  piece  bears  three  or  four  short,  finger-shaped,  articulating 
spines,  two  or  three  outwardly  disposed,  and  one  placed  near  the 
inner  base  between  adjoining  plates.  Along  the  outer  margin  of 
the  adambulacral  plates  and  abactinally  to  the  thick  finger-shaped 
spines  there  is  a  row  of  long,  slender,  flattened  and  longitudinally 
grooved  spines,  two  to  each  ossicle.  Orally  the  coin-shaped  adam- 
bulacral plates  are  somewhat  modified,  stand  less  erect  and  terminate 
in  pairs  of  subquadrangular  oral  armature  pieces. 

Ambulacral  grooves  wide,  shallow,  and  furrowed  medially  by  a 
narrow  angular  gutter.  Ambulacral  plates  of  adjoining  columns 
opposite  or  very  slightly  alternating,  the  pieces  narrow,  equaling 
in  number  the  adambulacrals,  slightly  overlapping  each  other 
proximally  and  partially  interlocking  in  the  medial  gutter.  The 
ambulacral  plates  continue  in  undiminished  size  to  the  compara- 
tively small  mouth,  are  highly  convex  and  club-shaped,  with  the 
attenuated  ends  laterally  disposed.  The  podial  openings  are  between 
the  attenuated  ends  of  adjoining  plates. 

Locality  and  formation. — In  the  Richmond  formation  at  Richmond, 
Indiana  (type-locality),  and  in  the  vicinity  of  Waynesville,  Ohio, 
where  Mr.  Harris  secured  six  more  or  less  mature  and  three  young 
individuals,  besides  numerous  fragments.  A  ray  of  this  species 
was  found  by  Mr.  U.  P.  James  near  Dayton,  Ohio.  In  the  Gurley 
collection  of  the  University  of  Chicago  there  is  a  young  specimen 
(No.  10978)  from  near  Ridgeville,  Warren  County,  Ohio. 


182  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

Remarks. — The  type-specimen  of  Palseaster  Jiarrisi  Miller  is  undoubt- 
edly a  Urasterella,  and  there  are  no  characters  other  than  size  by 
which  this  individual  can  be  separated  from  U.  grandis.  Of  about 
the  same  age  are  three  specimens  in  the  Harris  collection  and  another 
in  the  University  of  Chicago,  and  all  were  originally  referred  to 
P.  Jiarrisi.  One  of  these  is  nearly  again  as  large  as  the  type,  is  about 
one-half  the  size  of  U.  grandis,  and  measures  49  mm.  along  the  greater 
radius.  The  only  marked  difference  between  P.  Jiarrisi  and  U. 
grandis  is  the  smaller  number  of  adambulacral  plates  in  the  former, 
a  feature  common  to  the  young  of  many  fossil  starfishes  when  com- 
pared with  the  adults  of  the  same  species.  In  fact,  the  variation  in 
the  number  of  these  plates  in  the  two  largest  examples  (64  and  110) 
is  nearly  as  great  as  between  the  type  of  Palseaster  Jiarrisi  (22) 
and  the  smaller  of  the  two  largest  specimens  of  U.  grandis  (64). 

U.  grandis  is  closely  related  to  U.  pulchella  (Billings)  of  the 
Trenton  limestone.  These  species  are,  however,  easily  distinguished, 
not  only  by  the  different  geological  occurrences,  but  in  that  U.  grandis 
attains  a  much  larger  and  more  robust  growth.  The  latter  has  also 
many  more  abactinal  ossicles  with  longer  nonarticulating  spines, 
and  the  adambulacral  columns  have  from  60  to  110  plates,  instead 
of  from  36  to  60  as  in  U.  pulchella.  U.  grandis  appears  to  be  a 
direct  descendant  of  the  latter  and  has  varied  only  in  attaining  a 
larger  size  and  a  greater  number  of  plates. 

U.  grandis  is  also  closely  related  to  U.  ulrichi,  and  both  are  nearly 
of  one  size.  The  latter,  however,  has  the  rays  highly  convex  abac- 
tinally,  the  plates  are  smaller  but  as  strongly,  spinose,  and  there  are 
two  columns  of  larger  central  plates,  instead  of  one  as  in  U.  grandis. 
In  the  latter  in  the  mid-length  of  the  ray  there  are  about  9  plates 
in  a  column  in  10  mm.,  while  in  U.  ulrichi  there  are  from  11  to  12  in 
the  same  space. 

Cat.  Nos.  40885,  40887,  U.S.N.M. 

URASTERELLA  HUXLEYI  (Billings). 
Plate  29,  fig.  2. 

Stenaster  huxleyi  BILLINGS,  Geol.  Surv.  Canada,  Pal.  Foss.,  vol.  1,  1865,  p.  213, 
fig.  197. 

E  =  58  mm.,  r  =  5.5  mm.,  11  =  10. or.     Width  of  ray  at  base,  6  mm. 

Original  description. — " Deeply  stellate,  4  or  5  inches  across;  body 
small,  less  than  half  an  inch  in  diameter;  rays  long;  flexuous,  sub- 
cylindrical,  apparently  angulated  along  the  medium  line  on  the  upper 
side,  uniformly  tapering  to  an  acute  point.  On  the  dorsal  side  the 
rays  are  covered  by  a  multitude  of  small  subangular  plates,  each 
from  one-fourth  to  one-third  of  a  line  wide.  The  central  part  of  the 
body  is  not  well  preserved  in  the  only  specimen  collected;  but  it  is 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  183 

evident  from  a  view  of  the  plates  which  remain  that  they  are  here 
larger  and  more  convex  than  those  of  the  rays. 

" Diameter  of  the  body,  five  lines.  Length  of  each  ray,  If  inches. 
Width  of  the  rays  at  their  junction  with  the  body,  3  lines.  Depth 
of  the  rays  from  the  dorsal  to  the  ventral  side  of  the  body  apparently 
somewhat  less  than  the  width.  The  total  breadth  of  the  specimen, 
if  the  rays  were  straightened  out,  would  thus  be  about  4J  inches. 

"From  the  manner  in  which  the  rays  are  curved,  it  is  evident  that 
they  possessed  a  considerable  amount  of  flexibility.  The  specimen 
is  somewhat  distorted  by  pressure,  but  a  small  portion  of  one  of  the 
rays  near  the  body  seems  to  retain  its  natural  shape,  and  it  is  here 
obtusely  angulated  along  the  median  line.  The  transverse  section 
of  the  ray  should  be,  therefore,  subpentagonal.  There  is  still,  how- 
ever, some  doubt  on  this  point.  The  under  side  is  unknown. "  In 
places  where  the  specimen  is  broken  the  adambulacrals  are  seen  to 
be  as  in  other  species  of  Urasterella;  there  appear  to  be  about  60  or 
more  of  these  plates  in  each  column. 

Locality  and  'formation. — The  only  specimen  of  this  species  was 
found  by  Mr.  J.  Richardson  in  strata  of  Chazy  age  (bed  I  of  the 
Newfoundland  section)  at  Point  Rich,  Newfoundland.  The  holotype 
(No.  554)  is  in  the  Museum  of  the  Geological  Survey  of  Canada,  at 
Ottawa,  which  has  furnished  the  photograph  illustrating  the  specimen. 

Remarks. — The  holotype  was  seen  at  Ottawa  and  the  original 
illustration  found  to  be  a  fairly  accurate  reproduction  of  the  charac- 
ters of  the  fossil.  The  abactinal  side  of  the  disk  has  a  central  disk 
plate  that  is  large  and  tumid.  Around  it  is  a  circle  of  six  smaller, 
highly  convex  plates,  and  at  the  base  of  each  ray  medially  there  is 
another  single  large  tumid  plate,  the  basal  radial.  The  abactinal 
side  of  the  rays  is  highly  convex  and  somewhat  angulated  medially. 
The  ossicles  are  small  and  distinctly  arranged  in  quincunx,  of  which 
there  are  about  six  plates  in  each  diagonal  row  near  the  base  of  a  ray. 
In  other  words,  the  abactinal  characters  of  U.  huxleyi  are  very  much 
like  those  of  U.  ulrichi,  with  the  differences  that  in  the  latter  species 
the  prominent  disk  plates  are  smaller  and  there  are  more  columns 
of  smaller  ossicles  on  the  stouter  and  longer  rays.  Further,  in  U. 
ulrichi  there  are  two  columns  of  larger  abactinal  plates  along  the 
central  area  of  the  rays,  while  in  U.  huxleyi  all  the  ray  ossicles  are 
of  equal  size. 

TJ.  pulchellus  has  less  convex  and  more  slender  rays,  and  far  fewer 
abactinal  plates. 

URASTERELLA  ULRICHI,  new  species. 
Plate  29,  fig.  1;  plate  30,  figs.  6,  7. 

The  smallest  specimen  measures:  R  =  14  mm.,  r  =  4  mm.,  R  =  3.5r. 
The  best  preserved  specimen  measures:  R  =  45  mm.,  r  =  7.5  mm., 
R  =  6/*.  The  largest  specimen  measures:  R  =  78  mm.,  r=12  mm., 


184  BULLETIN   88,   UNITED  STATES   NATIONAL  MUSEUM. 

R  =  6.5r.  Width  of  ray  at  base  in  the  different  individuals  4,  7.5, 
and  9  mm.,  respectively. 

Rays  short  and  tapering  rapidly  when  young  but  at  maturity  very 
long,  highly  convex  abactinally,  and  tapering  very  slowly.  Disk 
comparatively  large  in  the  young  but  small  at  maturity  and  formed 
by  the  united  ends  of  rays. 

Abactinal  area  of  disk  and  rays  composed  of  numerous  small,  tumid, 
or  highly  spinose  plates  which  in  the  rays  are  arranged  distinctly 
in  columns  and  in  quincunx.  In  the  angles  between  all  of  the 
plates  are  left  subcircular  small  openings.  On  the  rays  medially 
there  are  two  columns  of  large  convex  plates,  variously  stellate  and 
not  produced  into  short,  blunt  rods.  These  are  the  supramarginals, 
and  between  them  are  a  few  widely  separated  plates  of  the  radial 
columns.  In  the  young  the  two  proximal  radial  plates  are  sepa- 
rated from  each  other  by  from  one  to  three  supramarginals,  while 
the  third  plate  is  separated  from  the  second  by  three  or  four  supra- 
marginals. In  a  mature  specimen  there  appear  to  be  about  eight 
of  these  radial  plates  on  each  ray  and  distally  they  are  separated 
from  one  another  by  five  supramarginal  ossicles.  On  each  side  of  the 
supramarginal  columns  are  from  one  (distally)  to  five  (proximally) 
columns  of  smaUer  or  accessory  ambital  plates.  In  a  full-grown 
specimen  there  are  11  to  12  in  10  mm.,  triangular  in  outline,  and 
drawn  out  into  short,  stout,  blunt  rods.  In  the  center  of  the  disk 
in  the  youngest  specimen  (probably  also  at  maturity)  there  is  a 
single  large  depressed  plate  around  which  is  a  first  circle  with  6 
plates  followed  by  a  second  having  16  pieces.  Of  the  latter,  5  are 
basal  radials,  10  basal  supramarginals,  and  1  the  madreporite. 
All  of  the  disk  plates  are  variously  stellate,  and  are  the  largest  plates 
of  the  abactinal  area,  the  size  gradually  diminishing  distally  along 
the  rays. 

Madreporite  concentrically  striate,  somewhat  smaller  than  the  basal 
supramarginals,  between  two  of  which  it  is  placed. 

Adambulacral  plates  seen  only  in  the  young  specimen,  very  strong, 
carinated,  subquadrate,  wider  than  long,  and  about  19  or  20  in  each 
column  10  mm.  long,  not  counting  the  oral  armature  pieces,  which  are 
subtriangular  in  outline.  Inside  of  each  pair  of  oral  armature  plates 
is  placed  a  very  stout  but  short  subcircular  spine  which  has  not  been 
observed  in  other  species.  No  other  spines  are  preserved. 

Ambulacral  furrows  very  narrow  and  deep,  concealing  the  ambu- 
lacral  plates. 

In  the  axils  of  the  youngest  specimen,  outside  of  the  adambulacrals, 
are  situated  three  prominent  plates,  the  proximal  one  being  the 
smallest.  On  each  side  of  these  along  the  ray  is  a  single  column  of 
plates  which  rapidly  diminish  in  size  and  separate  with  increasing 
interspaces  distally.  Their  number  can  not  be  made  out,  but  they 
appear  to  continue  to  the  tips  of  the  rays,  where  plates  occur  that 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  185 

are  not  ambital.  In  the  mid-length  of  the  ray,  however,  these  plates 
greatly  resemble  the  ambitals.  Judging  from  the  manner  in  which 
they  appear  distally,  their  form  and  constant  position  beside  and 
outside  the  adambulacrals  leads  to  the  conclusion  that  they  are  the 
inframarginals.  Whether  the  inframarginals  and  interbrachial  mar- 
ginals are  present  at  maturity  cannot  be  determined. 

Formation  and  locality. — Three  specimens  from  the  top  of  'the  Black 
River  limestone  immediately  beneath  the  Black  River  shale,  or  from 
the  Vanuxemia  bed  of  the  Black  River  (Mohawkian)  group  at  Minne- 
apolis, Minnesota.  The  specific  name  is  after  the  distinguished 
paleontologist,  Dr.  E.  O.  Ulrich,  who  found  all  the  specimens.  They 
are  in  the  United  States  National  Museum. 

Remarks. — This  species  is  distinguished  from  other  Ordovicic 
Urasterellas  by  the  few  and  widely  separated  plates  of  the  radial 
columns,  and  by  the  prominence  of  the  supramarginal  columns, 
which  in  the  other  species  are  not  distinguishable  from  the  ambitals. 
The  convexity  of  the  rays  abactinally  is  also  greater  than  in  the 
other  species  excepting  U.  Jiuxleyi,  but  that  species  is  further  dis- 
tinguished in  that  it  has  smaller  plates,  there  being  from  7  to  10  in 
5  mm.,  while  in  U.  ulrichi  there  are  only  5  to  6  in  the  same  space. 

U.  ulrichi  and  U.  grandis  attained  a  similar  large  size.  The  former, 
however,  is  from  a  much  lower  horizon,  has  very  convex  rays  abac- 
tinally, two  columns  of  larger  central  plates  (supramarginals)  instead 
of  one  (radial),  and  the  plates  are  smaller  and  therefore  more 
numerous. 

The  young  of  this  species  are  very  interesting  in  that  they  show 
distinctly  the  presence  of  large  inframarginal  and  interbrachial 
marginal  plates  in  the  axils.  In  U.  pulchella  none  of  these  plates 
have  been  seen  in  the  axils,  but  the  inframarginals  are  believed  to 
be  present  in  the  very  small  plates  which  are  indistinguishable  from 
the  ambital  pieces  situated  along  the  greater  length  of  the  rays  out- 
side of  the  adambulacrals.  The  same  appears  to  be  true  for  U.  grandis. 
The  young  of  U.  ulrichi  in  its  general  structure  reminds  one  much 
of  Mesopalseaster  sJiqfferi,  and  it  is  probable  that  Mesopalseaster  and 
Urasterella  are  derived  from  the  same  stock,  which  also  gave  rise  to 
Hudsonaster.  The  latter  retains  throughout  life  the  primitive  plate 
structure,  while  Mesopalseaster,  and  particularly  Urasterella,  develop 
in  various  ways  an  abundance  of  accessory  plates. 

The  best  preserved  specimen  of  U.  ulrichi  (pi.  29,  fig.  1)  has  two 
nearly  fully  grown  rays  and  three  short  stumps.  One  of  these  short  rays 
is  so  well  preserved  as  to  indicate  that  this  condition  is  not  due  to  poor 
preservation,  but  is  apparently  a  case  of  accidental  loss  of  parts 
during  life.  The  wound  has  been  healed,  but  no  regeneration  of  lost 
parts  has  taken  place,  as  is  so  common  in  similar  losses  among  the 
living  starfishes. 

Cat.  No.  60612,  U.S.N.M. 


186  BULLETIN   88,   UNITED   STATES  NATIONAL   MUSEUM. 

URASTERELLA  GIRVANENSIS,  new  species. 
Plate  28,  fig.  5. 

Tetraster,  sp.  ind.,  NICHOLSON  and  ETHERIDGE,  Mon.  Silurian  Foss.  Girvan  Dist., 

Ayrshire,  fasc.  3,  1880,  p.  325,  pi.  21,  figs.  9,  10. 
?  Eoactis  simplex  SPENCER,  Mon.  Brit.  Pal.  Asterozoa,  pt.  1  (Palaeontogr.  Soc.  for 

1913),  February,  1914,  p.  30,  pi.  1,  fig.  4. 
Urasterella  girvanensis  SCHUCHERT,  Fossilium  Catalogus,  Animalia,  pt.  3,  April, 

1914,  p.  44. 

Description  ~by  N.  and  E. — "Body  stellate,  with  slowly  tapering 
arms,  which  increase  little  in  width  throughout  their  whole  length  [the 
distal  ends  being  unknown];  upper  surface  unknown,  but  the  body 
was  convex  and  probably  granular.  [The  pieces  of  the  disk  are  seen 
through  the  mouth  and  consist  of  many  tiny  plates  arranged  in  more 
or  less  regular  circles  about  the  slightly  larger  central  ossicle.]  Ave- 
nues of  the  arms  broad,  and  not  bridged  over  by  any  of  the  plates  [this 
is  a  slip  of  the  pen,  for  the  ridged  ambulacralia  lie  horizontal  and 
deep  in  the  grooves  and  are  directly  opposite  one  another;  the  podial 
openings  are  fairly  large  and  in  the  usual  position  laterally];  marginal 
ambulacral  plates  [  =  adambulacrals]  moderately  convex,  trans- 
versely elongated,  or  oblong  in  form,  and  less  in  width  than  the 
ambulacral  plates;  those  in  the  angles  of  the  rays  are  the  largest,  and 
somewhat  more  elongated  than  the  others;  oral  plates  not  visible." 
The  interbrachial  areas  are  structurally  very  interesting  because  in 
each  one  there  is  a  single  narrow  but  long  axillary  interbrachial 
ossicle  that  distaily  margins  the  axil,  and  in  front  of  this  is  a  minute 
pair  of  ad  ambulacral  oral  armature  pieces.  On  either  side  of  the 
axillary  interbrachial  are  the  most  prominent  adambulacrals,  about 
five  in  number,  being  larger  than  the  other  distal  ones,  which  are 
considerably  narrower  and  of  fairly  uniform  size  throughout  the  rays. 

Formation  and  locality. — A  single  specimen  from  the  Upper  Ordo- 
vicic  at  Thraive  Glen,  Girvan,  Scotland.  A  good  wax  squeeze  of  the 
holotype  was  furnished  by  Doctor  Bather.  The  original  is  in  the  col- 
lection of  Mrs.  Robert  Gray,  at  Edinburgh,  Scotland. 

Remarks. — This  species  is  clearly  a  Ur  aster  ella,  a  fact  which  was 
also  noted  by  Nicholson  and  Etheridge,  as  they  state:  "In  some  of 
its  characters  it  approaches  very  closely  to  T.  (?)  asperrimus,  Salter, 
sp."  In  its  interbrachial  skeleton  U.  girvanensis  retains  youthful 
generic  characters,  seen  in  the  well-developed  interbrachial  axillary 
ossicles.  After  the  above  was  written  appeared  Spencer's  paper 
above  cited.  Before  the  writer  was  aware  of  this  work  he  had  pro- 
posed the  name  U.  girvanensis.  If  we  are  treating  of  the  same 
species  Spencer's  name  takes  precedence. 

Cat.  No.  60611,  U.S.N.M. 


REVISION    OF   PALEOZOIC    STELLEROIDEA.  187 

URASTERELLA  (?)  ASPERRTMA  (Salter). 

Palseaster  asperrima  SALTER,  Ann.  Mag.  Nat.  Hist.,ser.  2,  vol.  20,  1857,  p.  325, 

pi.  9,  fig.  1.— WRIGHT,  Mon.  British  Foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1 

(Palseontogr.  Soc.  for  1861),  1862,  p.  24,  fig.  15  (1). 
Palseaster  asperrimus  SALTER,  Mem.  Geol.  Surv.  Gt.  Britain,  vol.  3,  1866,  p.  289, 

pi.  23,  fig.  2. 

Palseaster  (?)  asperrimus  STURTZ,  Palseontographica,  vol.  32,  1886,  p.  91. 
fTetraster  asperrimus  NICHOLSON  and  ETHERIDGE,  Mon.  Silurian  Foss.  Girvan 

Dist,  Ayrshire,  fasc.  3,  1880,  pp.  320,  321,  324. 
Salteraster  asperrimus  STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50, 

1893,  pp.  43,  60. 

Nicholson  and  Etheridge  wrote  of  this  species  as  follows:  It 
"is  an  unsatisfactory  species.  The  specimens  in  the  Museum  of 
Practical  Geology  have  the  large  transverse  ossicles  very  apparent; 
but  as  to  whether  there  is  a  row  inside  or  outside  these,  or  both, 
we  are  by  no  means  certain.  It  appears,  however,  to  have  possessed 
only  four  rows."  Under  Tetraster  they  compare  this  species  with 
their  "T.  sp.  ind.,"  which  is  a  true  Urasterella  (U.  girvanensis) . 

It  seems  best  under  these  circumstances  to  refer  this  species  to 
Urasterella,  it  being  apparently  near  U.  grandis.  It  is  found  in  the 
Caradoc  or  Baia  sandstones  (Ordovicic),  near  Welshpool,  North 
Wales.  Should  it  prove  to  be  generically  different  from  Urasterella , 
then  the  name  Salteraster  Stiirtz  can  be  revived,  as  he  names  P.  asper- 
rimus as  the  genoholotype. 

URASTERELLA  (?)  CONSTELLATA  (Thorent). 

Asterias  constellata  THORENT,  Me"m.  Soc.  ge"ol.  de  France,  vol.  3,  1838,  p.  259, 
pi.  22,  fig.  7. 

The  original  figure  of  this  species  does  not  permit  of  determining 
its  generic  position.  It  is  described  as  having  but  one  range  of  plates 
on  each  side  of  the  ambulacral  grooves,  and  the  figure  seems  to 
indicate  the  presence  of  a  large  disk  with  well-defined  interbrachial 
arcs.  It  seems  to  have  more  of  the  characters  of  Urasterella  than 
of  any  other  genus. 

The  specimen  was  found  in  the  Siluric  ( ?  Lower)  strata  in  northern 
France  (Mondrepuis,  L'Aisne). 

URASTERELLA  RUTHVENI  (Forbes). 

Uraster  ruthveni  FORBES,  Mem.  Geol.  Surv.  Gt.  Britain,  vol.  2,  pt.  2,  1848,  p.  436; 

Mem.  Geol.  Surv.  United  Kingdom,  dec.  1,  1849,  p.  1,  pi.  1,  fig.  1;  in  McCoY, 

British  Pal.  Foss!,  1851,  p.  59.— MURCHISON,  Siluria,  1854,  fig.  39-3. 
Palxaster  ruthveni  SALTER,  Ann.  Mag.  Nat.  Hist.,  ser.  2,  vol.  20,  1857,  p.  326.— 

WRIGHT,  Mon.  British  Foss.  Echinod.,   Oolitic,  vol.  2,  pt.  1  (Palaeontogr. 

Soc.  for  1861),  1862,  p.  25. 
Urasterella  ruthveni  FORBES,  in  McCoY,  British- Pal.  Foss.,  1851,  p.  59. 

This,  the  genotype  of  Urasterella,  is  unfortunately  not  well  known, 
but  appears  to  be  congeneric  with  U.  grandis  and  U.  pulchella.  It 
occurs  in  the  Upper  Ludlow  beds  (Siluric),  near  Kendal,  Westmore- 
land, England. 


188  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

URASTERELLA  HIRUDO  (Forbes). 

Uraster  hirudo  FORBES,  Mem.  Geol.  Surv.  Gt.  Britain,  vol.  2,  pt.  2,  1848,  p.  464; 

Mem.  Geol.  Surv.  United  Kingdom,  dec.  1, 1849,  p.  3,  pi.  1,  fig.  4;  in  McCoy, 

British  Pal.  Foss.,  1851,  p.  59.— MURCHISON,  Siluria,  1854,  p.  221,  fig.  39-2. 
Palxaster  hirudo  SALTER,  Ann.  Mag.  Nat.  Hist.,  ser.  2,  vol.  20,  1857,  p.  326. — 

WRIGHT,  Mon.  British  Foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1  (Palseontogr. 

Soc.  for  1861),  1862,  p.  25. 
Urasterella  hirudo  FORBES,  in  McCoy,  British  Pal.  Foss.,  1851,  p.  59. 

This  small  species  has  much  the  appearance  of  being  the  young 
of  U.  ruthveni.  The  form  is  said  to  be  gregarious  and  is  associated 
with  that  species. 

URASTERELLA  SELWYNI  McCoy. 

Urasterella  selwyni  McCoy,  Geol.    Surv.  Victoria,  Prodr.    Pal.  Victoria,    dec.  1, 
1874,  p.  42,  pi.  10,  figs.  2,  2a,  3,  3a. 

Original  description. — "  Kays  five,  elongate,  gradually  tapering  from 
a  little  beyond  the  base,  which  is  slightly  contracted,  angulated  on 
the  upper  side  by  a  prominent  ridge  along  the  middle  of  each  ray, 
having  a  row  of  conical  tubercular  plates  (about  eight  in  two  lines), 
each  side  sloping  on  the  dorsal  aspect  from  the  middle  with  about 
three  rows  of  conical  tubercular  plates  rather  smaller  than  the  middle 
row.  The  five  axil  plates  small,  ovate,  triangular,  very  tumid. 
Adambulacral  plates  large,  extending  to  the  tubercular  margin, 
transversely  oblong,  about  twice  as  wide  as  long  (about  nine  in  two 
lines).  Ambulacral  plates  small,  in  a  deep  ambulacral  groove. 
Length  of  ray  from  mouth  to  tip,  six  lines;  greatest  width  near  base, 
1J  lines.  Surface  of  plates  granular. 

"This  beautiful  species  is  easily  known  by  its  strongly  angulated 
rays  on  the  dorsal  side.  The  traces  of  oral  plates  are  so  very  minute 
and  indistinct  that  I  can  not  give  their  character. 

"This  is  the  first  fossil  starfish  seen  in  Australia,  and  I  dedicated 
it  to  my  old  friend  Mr.  Selwyn,  formerly  Director  of  the  Geological 
Survey  of  Victoria,  and  now  Director  of  the  Geological  Survey  of 
Canada,  who  collected  it. 

"This  species  is  most  nearly  related  to  the  Uraster  ruthveni  of 
Forbes  from  the  Upper  Silurian  grits  of  Kendal  in  Westmoreland. 

"Common  in  the  fine  sandy  Silurian  beds  of  range  on  E.  side  of 
commonage  reserve,  Kilmore." 

Remarks. — This  is  clearly  a  species  of  UrastereTla.  ActinaUy  it 
has  in  each  axil  one  fairly  large  axillary  interbrachial  and  in  this 
recalls  the  same  structure  in  U.  girvanensis,  new  species. 

URASTERELLA  ASPERULA  (Roemer). 

Asterias  asperula  ROEMER,  Palaeontographica,  vol.  9,  1863,  p.  146,  pi.  24;  pi.  26, 

fig.  6;  pi.  27. 

Roemeraster  asperula  STURTZ,  Palseontographica,  vol.  32, 1886,  p.  85,  pi.  9,  figs.  4,  5. 
Protasteracanthion  primus  STURTZ,  Palseontographica,  vol.  32, 1886,  p.  90,  pi.  11, 

figs.  3,  3a. 

Remarks. — Of  this  species  there  are  two  specimens  in  the  United 
States  National  Museum  purchased  of  Stiirtz,  and  two  more  are 


REVISION   OF   PALEOZOIC    STELLEROIDEA.  189 

in  the  Tale  Museum  Collection.  These  show  both  sides  of  the  species. 
U.  asperula  is  said  to  be  common  in  the  roofing  slate  of  the  Lower 
Devonic  at  Bundenbach,  Germany. 

There  can  be  no  doubt  that  Asterias  asperula  Roemer  is  a  true 
UrastereTla.  All  the  generic  characters  are  shown,  even  the  longi- 
tudinally grooved  spines  and  the  rodlike  extensions  of  the  ambital 
plates.  For  further  remarks  on  this  species  see  generic  discussion. 

The  abactinal  structure  of  Roemeraster  asperulus  reminds  one  much 
of  UrastereTla  pulcJiella  of  the  Trenton,  which  is  the  least  specialized 
species  of  the  genus.  The  single  interbrachial  plate  retained  to 
maturity  reminds  one  of  the  young  of  U.  ulrichi.  In  this  character 
U.  asperula  appears  to  be  primitive.  In  the  proximal  third  of  the 
rays  in  U.  asperula  the  radial  columns  are  the  most  marked  and  the 
plates  continue  to  increase  in  size  toward  the  disk.  The  supramar- 
ginals  are  also  well  developed  proximally,  but  the  two  or  three 
proximal  plates  are  smaller  and  depressed,  so  that  the  ten  basals 
along  with  the  five  radials  do  not  make  so  prominent  a  ring  of  large 
ossicles  as  in  U.  pulcJiella  or  in  the  young  of  U.  ulrichi.  Distally 
the  rays  in  U.  asperula  have  the  plates  of  nearly  equal  size,  although 
the  columnar  and  quincuncial  arrangement  is  retained.  The  center 
of  the  disk  is  occupied  by  a  prominent  central  disk-plate  and  the 
first  ring  consists  of  five  radial  plates  as  in  U.  pulcJiella. 

Cat.  No.  59382,  U.S.N.M. 

URASTE3ELLA,  ne\7  species. 

In  the  paleontological  museum  of  Cornell  University  there  is  a 
large  slender-rayed  specimen  having  the  general  form  and  structure 
of  Urasterella.  There  is,  however,  so  little  of  the  actinal  detail  pre- 
served that  nothing  more  can  be  done  than  to  indicate  the  presence 
of  this  species. 

The  specimen  was  found  by  Mr.  J.  B.  Woodworth  at  Brookton, 
near  Ithaca,  New  York,  in  the  Upper  Devonic. 

URASTERELLA  MONTANA  (Stschurowsky). 

Palseaster  montanus  SCHONDORF,  Palseontographica,  vol.  56,  1909,  p.  324,  pi.  23, 
fig.  1;  pi.  24,  figs.  20-22  (complete  bibliography  cited  here). 

In  general  this  form  recalls  U.  grandis  but  is  somewhat  smaller  and 
stouter.  The  actinal  side  alone  is  known,  showing  a  wide  ambu- 
lacral  furrow  bordered  by  stout  columns  of  narrow  adambulacrals. 
All  of  the  ossicles  of  the  ambulacrals  and  adambulacrals  are  opposite 
one  another.  Oral  armature  decidedly  adambulacral  in  composition. 
Interradial  areas  described  as  having  "a  few  plates."  A  section 
through  a  ray  (Schondorf  s  fig.  22)  shows  that  abactinally  on  each 
side  of  the  radialia  there  are  four  columns  of  ossicles,  or  nine  in  all. 

Dimensions,  about:  E,  =  35  mm.,  r  =  6-7  nun.,  R  —  6r.  Width 
of  ray  at  mid-length  about  6  mm. 


190  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

Formation  and  locality  .—The  holotype  is  from  the  oldest  Upper 
Carboniferous  (Moscovian)  of  Mjatschkowa,  near  Moscow.  The 
specimen  is  now  in  the  Bergakademie  at  Berlin,  Germany. 

CALLIASTERELLID^E,  new  family. 

Calliasteridse  SCHONDORF,  Jahrb.  nassaulsch.  Ver.  Naturk.,  Wiesbaden,  vol.  63, 
1910,  p.  251. 

Cryptozonia  with  ophiurid  expression;  a  small  disk  with  primitive 
plate  arrangement  and  five  long,  very  flexible  rays,  with  radialia 
and  supramarginalia.  No  interbrachial  areas.  Ambulacrals  oppo- 
site. 

Contains : 

CalliastereUa,  new  name. 

Genus  CALLIASTERELLA,  new  name. 
Plate  31,  fig.  3,  text  fig.  11. 

Calliaster  mirus  TRAUTSCHOLD  (not  Calliaster  Gray  1840,  Echinoderma),  Nouv. 

Me"m.  Soc.  imp.  Nat.  Moscou,  vol.  14,  1879,  p.  108,  pi.  13,  figs.  3a-3ft,  4.— 

SCHONDORF,  Palaeontographica,  vol.  56,  1909,  p.  327,  pi.  23,  figs.  2-5;  pi.  24, 

figs.  1-18;  text  fig.  on  p.  328. 
CalliastereUa  SCHUCHERT,   Fossilium  Catalogus,   Animalia,  pt.  3,   April,   1914, 

p.  14- 

A  cryptozonian  asterid  with  the  general  expression  of  the  ophiurid 
Ony chaster. 

Description. — Disk  relatively  small,  primitive,  with  rather  large, 
decidedly  spiculate  ossicles.  Rays  five,  long  and  slender,  round 
in  section.  R  =  about  120  mm.,  r  =  30  to  35  mm.,  R  =  4r.  Width 
of  ray  at  mid-length  about  15  mm. 

Abactinal  disk  plates  in  form  and  position  as  in  figure  11.  There 
is  a  small  central  five-rayed  plate  with  the  rays  in  the  position  of  the 
five  arms.  Around  the  central  plate  is  a  first  ring  of  five  larger  basal 
radial  plates.  Then  comes  a  second  ring  of  ten  plates,  five  of  which 
are  the  second  basal  radialia;  the  other  five  are  interradial  in  posi- 
tion and  give  rise  hi  the  next  ring  to  the  ten  basal  inframarginal 
ossicles.  The  third  ring  has  five  radialia  and  ten  basal  inframargi- 
nals.  All  of  the  ossicles  in  the  three  rings  are  variously  six-rayed, 
with  large  rounded  openings  between  the  adjoining  spicular  ends. 
Between  each  pair  of  basal  inframarginals  are  inserted  single  elon- 
gate interradial  disk  plates. 

Madreporite  unknown. 

The  rays  abactinally  have  a  medial  column  of  transverse  radialia, 
and  alternating  with  these  on  either  side  are  columns  of  supra- 
marginals.  These  ossicles  are  of  peculiar  construction,  enabling 
the  rays  to  flex  about  as  in  Onychaster. 


REVISION   OF   PALEOZOIC    STELLEROIDEA.  191 

Ambulacralia  small,  adambulacralia  larger,  both  very  numerous 
in  each  column  and  in  their  disposition  opposite  one  another.  There 
are  no  inframarginals. 

Oral  armature  of  Cryptozonia  construction  and  very  much  as  hi 
living  Asterias  glacialis. 

Ocular  plates  probably  not  present. 

Genoholotype  and  only  species. — C.  mirus  (Trautschold)  (cita- 
tions as  above).  The  holotype  and  three  other  fragments  are  from 


\ 


R 


FIG.  ll.-*-THE  PLATES  OF  THE  DISK  OF  CALLIASTERELLA  MIRA.  SCHEMATIC.  AFTER  SCH&NDORF.  1,  CEN- 
TRODORSAL;  2,  BASAL  RADIALIA;  3,  SECOND  RADIALIA;  4,  THIRD  RADIALIA;  5,  BASAL  INFRAMARGINALS;  6, 
PAIRED  INFRAMARGINALS;  a,  POSSIBLE  POSITION  OF  ANUS;  mdp,  PROBABLE  POSITION  OF  MADREPORITE. 

the  Upper  Carboniferous  (Moscovian),  at  Mjatschkowa,  near  Moscow. 
The  holotype  is  in  the  University  of  Petrograd. 

Remarks.  —  There  is  no  other  Paleozoic  asterid  worked  out  in  such 
detail  as  is  Calliasterella.  Not  only  is  the  gross  skeleton  known,  but  the 
detailed  construction  of  all  of  the  essential  ossicles  and  spines  as 
well.  Quarto  pages  of  text  and  two  plates  are  devoted  to  the  skeleton. 

The  dorsal  skeleton  retains  primitive  construction,  and  although 
the  ossicles  are  much  modified,  their  general  orientation  is  that  of 
the  older  Phanerozonia. 

COMPSASTERIM;,  new  family. 

Specialized  Cryptozonia  with  decidedly  spicular  abactinal  skele- 
ton, recalling  that  of  Asterias.  Ambulacra  opposite  or  slightly 

50601°—  Bull.  88—15  -  13 


192  BULLETIN   88,  UNITED  STATES  NATIONAL  MUSEUM. 

alternating.     Rays  five,  long,  thick,  and  rounded  in  section.     Disk 
not  large. 

This  family  contains: 
Jaekelaster  Sturtz. 
Compsaster  Worthen  and  Miller. 

Genus  JAEKELASTER  Sturtz. 

Jaekelaster  SitfRTZ,  Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56,  1900,  pp. 
235-236,  pi.  4,  figs.  13-16. 

Generic  characters. — Rays  five,  thick  and  long,  55  mm.  in  length, 
16  mm.  in  greatest  breadth,  rounded  distally.  Disk  large.  Both 
rays  and  disk  devoid  of  marginal  plates. 

Abactinally  without  columns  of  plates,  entire  surface  decidedly 
and  abundantly  covered  with  "paxillae."  Madreporite  small, 
subcentral,  radiately  stria te. 

Ambulacral  furrows  wide,  widest  at  about  mid-length  and  nar- 
rowing both  distally  and  proximally.  Two  col  mns  of  podial 
openings.  Ambulacralia  narrow,  L-shaped,  slightly  overlapping 
and  slightly  alternating  proximally.  Adambulacrals  small,  di- 
rectly opposite  the  ambulacrals.  Outside  of  the  rays  the  integu- 
ment bears  spines  and  "paxillae"  abundantly. 

Genoliolotype  and  only  species. — J.  petaliformis  Sturtz  (citations 
as  above).  Lower  Devonic  of  Bundenbach,  Germany. 

Remarks. — This  genus  is  most  closely  related  to  Compsaster , 
in  fact  the  general  appearance  of  the  two  is  very  much  alike. 

Genus  COMPSASTER  Worthen  and  Miller. 

Plate  31,  figs.  1,  2. 
Compsaster  WORTHEN  and  MILLER,  Geol.  Surv.  Illinois,  vol.  7,  1883,  p.  327. 

Original  description. — "Body  stellate;  central  area  or  disk  com- 
paratively small;  rays  large,  long,  more  or  less  fusiform;  grooves 
deep  and  bordered  by  numerous  thin,  subcircular,  adambulacral 
plates.  The  ventral  side  of  the  typical  species  shows  about  six 
rows  of  plates  upon  each  side  of  the  ambulacral  furrows,  which 
have  a  regular,  transverse  as  well  as  longitudinal  arrangement. 

"This  genus  is  distinguished  from  all  others  in  the  family  [their 
Palseasteridse]  by  the  number  and  form  of  the  adambulacral  plates, 
by  the  great  number  of  disk  plates  upon  each  side  of  the  ambula- 
cral furrows,  and  by  the  general  form  of  the  body  and  rays." 

GenoTwlotype. — C.  formosus  Worthen  and  Miller.  It  is  also  the 
only  named  species  of  the  genus. 

The  adambulacral  plates  in  Compsaster  appear  to  be  much  as 
in  UrastereUa  and  both  genera  agree  in  having  no  distinct  inframar- 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  193 

ginal  plates.  The  ambit al  plates  are  very  numerous,  showing  a  dis- 
tinct progression  to  far  more  numerous  columns  of  plates  than  in 
Urasterella.  They  also  appear  like  those  in  this  genus.  It  is  prob- 
able that  the  abactinal  area  when  it  is  known  will  be  seen  to  have 
spicular  ossicles  like  those  of  the  ambital  areas. 

COMPSASTER  FORMOSUS  Worthen  and  Miller. 

Plate  31,  figs.  1,  2. 

Compsaster formosus  WORTHEN  and  MILLER,  Geol.  Surv.  111.,  vol.  7,  1883,  p.  327, 
pi.  31,  figs.  2a,  26. 

Original  description. — "Body  deeply  stellate;  central  disk  com- 
paratively small;  rays  rigid,  large,  fusiform,  more  than  twice  as  long 
as  the  diameter  of  the  central  disk,  and  terminating  abruptly  in  an 
obtuse  point.  The  typical  specimen  furnishes  the  following  meas- 
urements: Diameter  of  the  body,  0.72  inch;  length  of  ray  from  cen- 
tral part  of  disk,  1.78  inches;  diameter  of  the  ray  at  its  junction  with 
the  body,  0.41  inch. 

"Ambulacral  grooves  deep;  ossicles  rather  small;  adambulacral 
plates  very  numerous,  and  consisting  of  series  of  thin  plates  upon 
each  side  of  the  ambulacral  furrows,  which  are  rounded  upon  the 
exterior,  prolonged  below,  and  each  bear  a  short,  sharp  spine  on  the 
upper  part  of  the  inner  side,  directed  toward  the  apex  of  the  ray. 
There  are  about  eighty  adambulacrak  upon  each  side  of  the  furrows, 
and  they  dimmish  very  slowly  in  size  toward  the  apex,  after  passing 
the  fusiform  enlargement  of  the  ray. 

"The  disk-plates  abut  upon  the  adambulacrals  in  a  straight  line; 
they  are  subquadrangular,  or  polygonal,  and  each  bears  a  strong 
central  spine.  Six  longitudinal  rows  appear  on  the  ventral  side  on 
each  side  of  the  ambulacral  furrows;  they  are  somewhat  uniform  in 
size,  arranged  in  transverse,  as  well  as  longitudinal  order,  and  are 
about  two-thirds  as  numerous  in  a  longitudinal  row  as  the  plates  in 
an  ambulacral  series. 

"Oral  plates,  madreporiform  tubercle,  and  dorsal  side  unknown, 
except  so  far  as  we  may  judge  of  the  spinous  character  of  the  plates 
from  those  visible  on  the  ventral  side. 

"This  large  and  beautiful  species  is  so  distinct  from  any  hitherto 
described  that  no  comparison  is  necessary  for  the  purpose  of  identifi- 
cation. 

"Position  and  locality. — Okaw  bluffs,  between  Chester  and  Kaskas- 
kia,  Randolph  county,  Illinois;  from  the  second  division  of  the  Chester 
limestone. 

"Illinois  vState  coUection  of  1880,  by  A.  H.  Worthen,  No.  2476." 

The  writer  has  not  been  able  to  consult  the  type-specimen. 


194  BULLETIN   88,   UNITED   STATES   NATIONAL  MUSEUM. 

COMPSASTER,  new  species. 

Professor  Weller  collected  an  excellent  asterid  at  Fountain  Creek, 
Waterloo,  Illinois  (No.  14395,  University  of  Chicago  collection), 
showing  the  entire  actinal  side  of  a  form  that  is  nearest  to  O.formosus. 
It  is,  however,  a  smaller  and  more  slender  species,  but  until  the 
abactinal  surfaces  of  both  species  are  known,  one  can  not  say  that 
they  are  certainly  of  the  same  genus. 

Measurements :  R  =  20.5  mm.,  r  =  4.5  mm. 

SCHUCHERTIID^E,  new  family. 

Specializing  Cryptozonia  with  well-developed  pentagonal  inter- 
brachial  arcs.  Inframarginals  well  developed  in  the  proximal  regions 
where  they  remain  adjoining  the  adambulacrals.  Interbrachial 
and  abactinal  areas  composed  of  small,  more  or  less  closely  adjoining 
plates  without  regular  arrangement. 

Madreporite  unknown. 

Contains : 

Schuchertia  Gregory. 

Remarks. — This  family  is  the  most  ancient  and  primitive  of  all 
large-disked  or  pentagonal  starfishes  devoid  of  marginals.  In 
Schuchertia  the  first  appearing  inframarginals  are  retained  through- 
out life  and  remain  adjoining  the  adambulacrals  in  the  axillary 
regions.  These  columns  distally  become  less  distinct  and  in  the 
outer  third  of  the  rays  are  not  distinguishable  as  inframarginals 
from  the  other  smaller  ossicles  of  the  interbrachial  areas.  This 
therefore  indicates  that  during  the  growth  of  Schuchertia  the  infra- 
marginals  are  in  the  process  of  elimination  and  in  later  forms  seem 
to  be  completely  disguised  or  lost.  Then  the  plates  of  the  inter- 
brachial and  abactinal  areas,  while  small,  are  usually  strong,  rarely 
spicular  or  stellate  but  never  decidedly  so,  while  in  later  genera  the 
ossicles  either  break  up  into  smaller  and  smaller  plates,  even  into 
granules,  or  are  spicular  or  thorny  pieces.  Even  the  adambula- 
crals which  are  well  developed  in  Schuchertia  may  become  greatly 
modified  and  almost  eliminated. 

In  seeking  for  an  ancestor  for  this  family,  it  is  plain  that  it  came 
from  a  stock  like  Hudsonaster.  This  genus  actinally  has  columns 
of  ambulacral,  adambulacral,  and  inframarginal  plates;  abactinally, 
inframarginal,  supramarginal,  and  radial  columns  of  plates.  In 
addition  there  are  five  axillary  marginals,  and  on  the  disk  a  ring  of 
five  basal  radial  and  five  interradial  plates  giving  rise  to  the  radial 
and  supramarginal  columns.  The  first  step  from  Hudsonaster  toward 
Schuchertia  would  be  a  form  of  the  former  genus  introducing  small 
ambital  plates.  This  type  is  as  yet  unknown,  but  is  suggested  in 
UrastereTla.  The  progressive  introduction  of  ambital  plates  and  no 


REVISION   OF   PALEOZOIC    STELLEROIDEA.  195 

development  of  small  interbrachial  pieces  will  tend  to  keep  the 
inframarginals  beside  the  adambulacrals.  This  is  the  case  in  Schuch- 
ertia  where  the  axillary  marginals  are  also  retained,  but  this  genus 
has  progressed  considerably  beyond  this  stage,  since  the  inframar- 
ginals fail  to  develop  in  the  later  growth,  while  the  supramarginals 
and  radials,  as  columns,  are  no  longer  distinguishable  as  such  in 
any  part  of  the  individuals.  The  tendency  of  departure  from  Hudson- 
aster  therefore  seems  to  be  toward  the  breaking  up  and  elimination 
of  its  essential  structure  into  a  mass  of  variously  arranged  small 
pieces,  except  the  ambulacrals,  which  remain  as  columns  of  stout 

plates. 

Genus  SCHUCHERTIA  Gregory. 

Plates  32  and  33. 

Palasterina  BILLINGS  (part,  not  McCoy  or  Salter),  Geol.  Surv.  Canada,  Can.  Org. 

Rem.,  dec.  3,  1858,  p.  76. 

Schuchertia  GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6,  August,  1899,  p.  351. 
Trentonaster  STURTZ,  Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56,  1900,  pp. 

224,  225  (based  on  same  genoholotype  as  Schuchertia). 

Original  description. — "Palseasterinidse  with  tessellate  exoskeleton; 
the  rays  are  short  and  the  general  shape  is  pentagonal.  R:  r  as  2:1. 
Interradial  plates  numerous,  polygonal.  Adambulacral  plates  large 
and  hexagonal.  Ambulacral  furrow  tapering  uniformly  toward  the 
distal  end. 

"  Allied  to  Palseasterina  by  the  general  form  of  the  body  and  the 
absence  of  the  marginal  plates." 

Emended  description. — Rays  five,  short  and  slender.  General 
form  pentagonal.  Disk  large,  with  well-developed  interbrachial 
arcs. 

Abactinal  area  composed  of  very  numerous,  small,  tumid,  non- 
stellate  plates  which  are  arranged  in  quincunx  or  columns.  There 
are  no  radial,  supramarginal,  or  ambital  plates  recognizable  as  such, 
nor  is  the  margin  bounded  by  columns  of  inframarginals. 

Madreporite  indistinguishable  amongst  the  abactinal  plates. 

Actinally  the  ambulacral  furrows  are  very  narrow,  bounded  by 
columns  of  adambulacral  plates.  Adjoining  these  in  the  proximal 
regions  are  distinct  " axillary  marginals"  and  inframarginals,  the 
latter  distally  becoming  smaller,  and  these  continue  either  closely 
adjoining  or  are  separated  from  one  another  by  increasing  interspaces. 
In  the  latter  case  they  are  not  readily  distinguished  from  the  inter- 
brachial accessory  plates. 

Interbrachial  areas  occupied  by  numerous  small  accessory  plates 
and  like  those  of  the  abactinal  area  with  which  they  are  continuous. 

Ambulacral  plates  apparently  slightly  alternating. 

Genoliolotype  (of  both  Schuchertia  and  Trentonaster). — Palasterina 
stellata  Billings.  The  generic  description  is,  however,  largely  based 
on  S.  laxata,  new  species. 


196  BULLETIN   88,  UNITED  STATES  NATIONAL  MUSEUM. 

Distribution. — Ordovicic  and  Siluric  of  North  America.  Con- 
tains the  following  species: 

S.  stellata  (Billings).     Trenton,  Ottawa,  Canada. 

8.  laxata,  new  species.     Richmond  of  Ohio. 

S.  ordinaria,    new    species.     Basal    Siluric.*    Girardeau    lime- 
stone, Alexander  County,  Illinois. 

Remarks. — Schuchertia  need  only  be  compared  with  Petraster  and 
Palasterina.  The  former  differs  in  that  the  incomplete  columns  of 
inframarginals  adjoin  the  adambulacrals  and  are  not  separated  from 
them  by  interbrachial  accessory  plates  as  in  the  other  two  genera. 
Petraster  is  readily  distinguished  by  the  prominent  columns  of  infra- 
marginals  bounding  the  entire  animal  and  abactinally  by  the  distinct 
columns  of  radial,  supramarginal,  and  ambital  plates.  In  Schuchertia 
the  plates  of  the  abactinal  and  interbrachial  areas  are  alike  and 
not  distinguishable  into  the  kinds  of  columns  just  mentioned  for 
Petraster. 

The  fact  that  in  ScJiuchertia  the  " axillary  marginals7'  and  infra- 
marginals  remain  beside  the  adambulacrals  seems  to  indicate  its 
origin  in  forms  like  Hudsonaster.  The  generic  structure  of  the  latter 
is  retained  in  Schuchertia,  to  which  is  added  along  the  margin  (mainly 
axillary)  a  series  of  interbrachial  accessory  plates.  The  generic 
structure  of  Hudsonaster  is  also  retained  in  Petraster,  but  here,  unlike 
those  in  Schuchertia,  the  interbrachial  accessory  plates  are  developed 
between  the  inframarginals  and  adambulacrals,  forcing  these  columns 
apart.  The  phylum  starting  in  Schuchertia  is  not  a  prolific  one,  but 
the  other,  Palasterinidse,  whose  inframarginals  are  true  marginals, 
is  not  only  more  prolific  in  genera  but  also  has  a  longer  geological 
range.  Beginning  in  Petraster  of  the  Ordovicic,  it  is  continued  in 
the  Siluric  in  Lindstromaster  and  Palasterina. 

SCHUCHERTIA  STELLATA  (Billings). 
Plate  32,  fig.  2;  plate  33,  fig.l. 

Palasterina  stellata  BILLINGS,  Geol.  Surv.  Canada,  Rep.  Progress  for  1853-1856, 
1857,  p.  290;  Geol.  Surv.  Canada,  Can.  Org.  Rem.,  dec.  3,  1858,  p.  76,  pi.  9, 
figs,  la,  16.— WRIGHT,  Mon.  British  Foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1, 
(Pakeontogr.  Soc.  for  1861),  1862,  p.  27,  fig.  16  on  p.  26.— QUENSTEDT,  Petre- 
factenkunde  Deutschlands,  vol.  4,  1876,  p.  74,  pi.  92,  fig.  34. 

Trentonaster  stellata  STURTZ,  Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56, 
1900,  pp.  217,  224,  225. 

Description  of  1858. — "Pentagonal;  disk  about  one-half  of  the  whole 
diameter;  ambulacral  grooves  narrow  and  deep,  bordered  on  each 
side  by  a  row  of  small,  nearly  square  adambulacral  plates;  a  second 
row  consisting  of  disk  plates  extends  nearly  to  the  end  of  each  ray, 
the  remainder  of  the  disk  covered  with  smaller  plates.  All  of  these 
plates  are  solid  and  closely  fitted  together;  the  disk  plates  in  the 


KEVISION    OF   PALEOZOIC    STELLEKOIDEA.  197 

angles  in  contact  with  the  oral  plates  are  much  larger  than  any  of 
the  others. 

"In  the  only  specimen  in  the  collection  the  length  of  the  rays 
measured  along  the  ambulacral  grooves  is  three  lines;  number  of 
adambulacral  plates  on  each  side  of  the  grooves  sixteen;  the  rays 
diminish  somewhat  rapidly  in  size,  and  terminate  in  a  rounded  point; 
diameter  of  the  disk  four  lines.  The  plates  are  all  a  little  worn,  so 
that  the  character  of  their  surfaces  can  not  be  observed;  they  were 
probably  nearly  smooth." 

Emended  description. — Measurement  of  the  immature  type-speci- 
men: R  =  6  mm.,  r  =  3  mm.  Larger  specimen:  R  =  9  mm.,  r=4  mm. 

Abactinal  area  composed  of  a  series  of  plates  which  are  more  or 
less  closely  adjoining  and  on  the  rays  are  arranged  in  distinct  but 
twisted  columns.  This  twisting  is  due  to  the  insertion  of  new  columns 
of  plates,  always  on  the  right  side,  crowding  the  older  ones  to  the  left. 
The  plates  on  the  rays  are  subquadrangular  to  elongate  subquad- 
rangular,  increasing  in  size  proximally,  and  on  the  disk  are  largest 
and  generally  subcircular  in  outline,  or  faintly  stellate.  The  plates 
appear  to  be  smooth.  At  the  apex  of  the  ray  are  two  somewhat 
larger  plates  followed  by  three  columns  and  on  each  side  of  these 
there  are  two  other  columns  of  ossicles.  Near  the  beginning  of  the 
interbrachial  arcs  the  rays  have  from  se^en  to  eight  columns  of  plates. 

Madreporite  not  distinguished  among  the  abactinal  plates. 

Actinally  the  most  conspicuous  columns  are  the  adambulacrals 
bounding  the  very  narrow  ambulacral  grooves.  These  ossicles  are 
subquadrangular  in  outline  near  the  base  of  the  column,  but  become 
wider  than  long  distally;  there  are  about  15  in  a  column,  terminating 
proximally  in  two  larger,  prominent,  wedge-shaped  plates  of  the 
oral  armature.  Interradially  upon  each  pair  of  oral  pieces  is  placed 
a  large,  single,  pentagonal  plate  (holds  the  position  of  axillary 
interbrachials),  against  which  rest  two  diverging  inframarginal 
columns,  each  with  13  or  14  ossicles,  and  these  columns  continue 
adjoining  the  adambulacrals.  Before  attaining  the  distal  ends  of  the 
rays  they  gradually  become  smaller  and  pass  over  to  the  abactinal 
side.  Other  actinal  disk  plates  are  also  present,  but  apparently  are 
arranged  in  quincunx,  and  are  smooth  like  those  of  the  abactinal  side. 

Ambulacrals  unknown. 

Formation  and  locality. — Ordovicic.  The  holotype  (No.  1399,  Geol. 
Surv.  Canada  collection)  showing  the  actinal  area  was  found  by  Mr. 
E.  Billings,  at  Ottawa.  Another  specimen,  also  in  the  Museum  of 
the  Geological  Survey  of  Canada,  and  showing  the  abactinal  area,  was 
found  by  Mr.  J.  S.  Stewart  on  Governor  General  Bay,  near  New 
Edinburgh,  Canada. 

Remarks. — This  little  Ordovicic  asterid  is  distinguishable  from 
other  species  with  large  interbrachial  arcs  in  that  it  is  devoid  of  all 
marginal  and  radial  columns  of  plates.  From  S.  laxata  it  is  differ- 


198  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

entiated  by  its  smaller  size,  less  numerous  plates,  and  by  the  rela- 
tively greater  size  of  the  disk  ossicles. 

SCHUCHERTIA  LAXATA,  new  species. 

Plate  32,  fig.  3*  plate  33,  figs.  2,  3. 

The  best  specimen  measures:  R  =  18  mm.,  r=  6  mm.,  R  =  3r.  The 
University  of  Chicago  individual:  R  =  23  mm.,  r=  about  8  mm. 
R  =  2.8r.  Other  specimens  indicate  a  growth  twice  as  large  as  the 
former  one. 

Rays  short  and  slender.  Disk  and  interbrachial  arcs  large  but  not 
nearly  so  large  as  in  Petraster  speciosus.  Six  specimens  are  known, 
four  of  which  are  poorly  preserved  and  but  a  jumble  of  plates.  The 
specific  name  is  given  to  indicate  the  generally  separated  condition 
of  the  plates. 

Abactinal  areas  of  rays  and  disk  composed  of  very  numerous, 
small  but  irregularly  sized,  subquadrate  or  diamond-shaped,  slightly 
pustulose  plates.  The  arrangement  is  mainly  in  quincunx  but  a 
columnar  arrangement  is  also  noticeable. 

Madreporite  not  distinguishable   amongst   the   abactinal   plates. 

Ambulacral  furrows  very  narrow,  hardly  revealing  the  carinated 
ambulacral  plates.  The  podial  openings  are  between  the  plates 
along  their  lateral  corners. 

Adambulacral  plates  very  convex,  a  little  wider  than  long,  with 
the  inner  edge  more  or  less  pointed,  against  which  terminates  the 
carina  of  the  ambulacral  pieces.  There  are  about  15  of  the  former 
plates  in  15  mm.  along  the  base  of  the  columns.  Actinally  the  adam- 
bulacral  columns  are  the  most  conspicuous,  since  the  inframarginals 
beyond  the  mid-length  of  the  former  columns  appear  not  to  be 
separable  from  the  adjoining  interbrachial  pieces.  The  inner  side  of 
the  adambulacrals  bears  tufts  of  short  blunt  spines. 

Inframarginals  recognizable  as  such  only  within  the  axils  where 
they  adjoin  the  ad  ambulacral  columns.  Just  within  each  axil  there 
is  a  large  single  plate  (axillary  marginal)  against  which  rest  the  infra- 
marginal  columns.  These  plates  decrease  rapidly  in  size  distally  and 
are  soon  separated  from  one  another  so  that  the  tenth  piece  from  the 
axil  is  indistinguishable  in  shape  and  size  from  the  interbrachials. 

Interbrachial  accessory  plates  very  numerous,  smallest  in  the 
inner  axillary  areas  and  thence  increasing  rapidly  to  a  size  maintained 
throughout  the  interbrachial  areas.  In  form  they  are  either  diamond- 
shaped  or  subquadrate,  centrally  tumid,  and  each  plate  seems  to  have 
borne  one  central  and  two  or  three  lateral  spines. 

Formation  and  locality. — Five  specimens  are  in  the  Harris  collec- 
tion, all  from  the  Richmond  (Waynesville) ,  in  the  vicinity  of  Waynes- 
ville,  Ohio.  A  fine  specimen  showing  the  abactinal  area  (University 
of  Chicago  collection,  No.  10982)  was  found  7  miles  north  of  Hamilton, 


REVISION   OF   PALEOZOIC    STELLEROIDEA.  199 

Ohio.  Another  fragment  was  found  by  Mr.  E.  H.  Vaupel  at  Oxford 
in  the  same  State. 

Remarks. — The  only  Upper  Ordovicic  species  with  which  Schu- 
cTiertia  laxata  can  136  confounded  is  Petraster  speciosus.  However, 
there  is  one  fundamental  difference  between  them,  so  that  even 
fragments  can  be  distinguished.  In  P.  speciosus  the  inframarginals 
are  very  conspicuous  and  bound  the  outer  margin  of  the  entire  animal, 
while  in  S.  laxata  there  are  no  columns  of  marginal  plates,  since 
the  inframarginals  closely  adjoin  the  adambulacrals.  In  other 
words,  in  the  former  species  the  interbrachial  accessory  plates  are 
between  the  adambulacrals  and  inframarginals,  while  in  the  latter 
form  these  pieces,  which  are  also  far  more  numerous,  are  all  outside 
of  the  inframarginals.  The  generally  disjointed  condition  of  the  plates 
in  S.  laxata  will  probably  always  distinguish  it  from  P.  speciosus. 

Cat.  Nos.  60613,  60623,  U.S.N.M. 

SCHUCHERTIA  ORDINARIA,  new  species. 

A  regular  species  of  Schuchertia. 

The  holotjTpe  shows  the  abactinal  side  only.  R  =  1 1  mm.,  r  =  about 
6.3  mm. 

This  species  is  most  closely  related  to  S.  laxata,  but  is  smaller  and 
with  a  comparatively  larger  disk.  Therefore  the  rays  do  not  protrude 
beyond  the  disk  so  far  as  in  the  latter  form.  Abactinal  skeleton  con- 
sists of  minute  tumid  ossicles  that  are  more  cut  along  their  edges 
than  in  S.  laxata,  and  therefore  more  spicular. 

The  specimen  can  not  be  freed  of  the  adhering  clay  sufficiently  to 
make  an  instructive  photograph,  and  is  therefore  not  illustrated. 

Formation  and  locality. — The  holotype  is  from  the  basal  Siluric 
Girardeau  limestone,  Alexander  County,  Illinois.  It  is  in  the  Gurley 
collection  of  the  University  of  Chicago  (No.  10992). 

Family  PALASTEBISCID^E  Gregory. 

Palssbrisingidx  STURTZ,  Palaeontographica,  vol.  36,  1890,  p.  246. 
Palsechinasteridse  STURTZ,  Palaeontographica,  vol.  36,  1890,  p.  246,  also  p.  247. 
Palasteriscidse  GREGORY,  Treat.  Zool.,  vol.  3,  Echinoderma,  1900,  p.  257. 

Specialized  Cryptozonia  with  very  large  interbrachial  arcs.  Abacti- 
nal and  interbrachial  areas  either  with  a  smooth  membrane  or  granu- 
lar and  thorny.  No  radial  or  supramarginal  columns  of  ossicles. 
Inframarginals  not  present  in  any  position.  Madreporite  probably 
always  actinal.  Ambulacrals  alternating  or  opposite;  adambulacrals 
more  or  less  modified,  but  remain  adjoining  the  ambulacrals. 
Contains : 

Palasteriscus  Sturtz. 
Echinasterella  Stiirtz. 
Loriolaster  Sturtz. 
Cheiropteraster  Sturtz. 
For  remarks  on  the  course  of  development,  see  Schuchertiidse. 


200  BULLETIN   88,   UNITED   STATES   NATIONAL  MUSEUM. 

Genus  PALASTERISCUS  Sturtz. 

'  Palasteriscus  STURTZ,  Palaeontographica,  vol.  32,  1886,  p.  95,  pi.  14,  fig.  1;  vol.  36, 
1890,  p.  223,  pi.  28,  figs.  23-236;  pi.  29,  fig.  24;  Verh.  naturh.  Ver.  preuss. 
Rheinl.,  etc.,  vol.  50,  1893,  pp.  44,  61. 

This  genus  differs  from  Loriolaster  in  being  more  decidedly  stellate, 
with  longer  and  more  slender  rays  and  less  extensive  interbrachial 
arcs.  The  abactinal  and  interbrachial  areas  are  made  up  of  innumer- 
able, small,  variously  shaped,  loosely  interlocking,  stellate  plates. 
These  areas  in  Loriolaster  appear  to  be  smooth. 

Madreporite  very  large,  actinal. 

The  genoholotype,  P.  devonicus  (same  citations  as  above),  is  the 
only  species  and  is  very  rare  in  the  Lower  Devonic  roofing  slates  of 
Bundenbach,  Germany. 

Cat.  No.  59389,  U.S.N.M. 

Genus  ECHINASTERELLA  Sturtz. 

Echinasterella  STURTZ,  PalseontograpMca,  vol.  36, 1890,  p.  225,  pi.  28,  figs.  26,  26a, 
27;  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50,  1893,  pp.  53,  73. 

This  form  seems  to  be  closely  related  to  Palasteriscus ,  and  without 
material  for  examination  it  is  difficult  to  point  out  the  differences 
supposed  to  be  generic.  Sturtz  describes  the  ambulacrals  as  oppo- 
site, but  his  figures  26  and  27  show  that  they  are  slightly  alternating. 

The  genoholotype,  of  which  three  imperfect  examples  are  known, 
is  E.  sladeni  (same  citations  as  above).  It  is  from  the  Lower  Devonic 
of  Bundenbach,  Germany.  Another  form  which  probably  belongs 
here  is  E.  (?)  darwini  Clarke,  from  the  Devonic  of  Brazil. 

ECHINASTERELLA  (?)  DARWINI  Clarke. 

Echinasterella  ?  darwini  CLARKE,  Monog.,  I,  Serv.  Geol.  Min.  Brasil,  1913,  p.  315, 
pi.  27,  figs.  9-12;  Bull.  N.  Y.  State  Mus.,  No.  164,  pi.  34,  figs.  1-3. 

Original  description. — "Of  this  fine  starfish  the  collections  con- 
tain two  specimens,  one,  that  from  which  our  illustrations  are  taken, 
a  sharp  cast  of  an  oral  surface  with  the  arms  extended,  in  a  shale 
sufficiently  compact  to  permit  a  squeeze  to  be  made  of  the  entire  ex- 
posure. The  other  is  a  considerably  distorted  individual  also  chiefly 
with  oral  exposure.  I  have  placed  the  species  only  provisionally  with 
Sturtz's  genus  EchinastereUa,  which  was  described  from  the  Bunden- 
bach slates,  feeling  that  in  all  probability  both  this  species  and  its 
associated  Aspidosomaf  pontis  will  be  found  on  close  analysis  by 
expert  students  of  the  Asteroidea  to  pertain  to  other  genera.  The 
structural  features  presented  by  E.f  darwini  are  as  follows:  The 
oral  surfaces  of  the  arms  are  very  broad,  the  ambulacral  grooves 
narrow,  and  the  plates  arranged  opposite  each  other.  The  ambulacral 
plates  are  turned  obliquely  inward  and  are  broadened  at  their  inner 
ends.  As  preserved  these  show  only  their  upper  edges  except  where 


REVISION   OF  PALEOZOIC    STELLEROIDEA.  201 

turned  somewhat  more  obliquely  along  the  food  groove.  At  the 
edges  of  these  very  broad  ambulacral  areas  the  adambulacral  plates 
project  in  a  single  row  on  each  margin,  as  rounded  nubs  or  thickened 
elongated  ridges,  from  each  of  which  project  not  less  than  two  and 
probably  three  spines.  In  no  place  is  the  aboral  surface  of  the  starfish 
presented,  but  the  madrepore  plate  is  distinctly  shown  in  one  of  the 
axillae,  indicating  its  ambulacral  position.  This  plate  is  round,  con- 
vex, obscurely  radiopunctate,  and  somewhat  ridged.  The  oral  appara- 
tus is  indicated  by  thickened  plates  at  the  axillae,  but  their  structure 
in  detail  can  not  be  made  out.  The  example  serving  as  the  type  of  this 
species  has  a  radial  length  from  center  of  mouth  to  tip  of  longest  arm 
of  54  mm." 

Formation  and  locality. — From  the  Devonic  of  Ponta  Grossa, 
Brazil. 

Genus  LORIOLASTER  Sturtz. 

Loriolaster  STURTZ,  Palaeontographica,  vol.  32,  1886,  p.  94,  pi.  12,  figs.  3,  3a,  4; 
pi.  13,  figs.  1,  la,  2,  2a;  vol.  36,  1890,  p.  208,  pi.  26,  figs.  36,  4a;  Verh.  naturh. 
Ver.  preuss.  Rheinl.,  etc.,  vol.  50,  1893,  pp.  47,  63. 

Generic  description. — Animal  large,  five-rayed,  widely  pentagonal, 
with  very  large  interbrachial  arcs  entirely  inclosing  the  rays.  No 
marginal  plates  and  seemingly  with  a  parchment-like  integument  on 
the  abac  tin  al  side  and  in  the  large  interbrachial  areas.  The  plates 
seen  on  the  abactinal  side  resemble  the  aspect  of  the  actinal  plates. 

Madreporite  unknown. 

Ambulacral  plates  alternating,  numerous,  considerably  wider  than 
long,  with  the  podial  openings  indeterminate. 

Adambulacrals  about  as  numerous  as  the  ambulacrals,  sickle- 
shaped,  greatly  elongated  laterally  and  bearing  club-shaped  carinse 
(the  regular  arrangement  of  the  latter  seems  to  preclude  their  being 
articulating  spines)  which  have  on  their  outer  lateral  ends  needle-like 
spines. 

Oral  armature  pieces  large,  described  as  ambulacral. 

The  only  known  species  is  L.  mirdbilis  Sturtz  (same  citations  as 
above),  from  the  Lower  Devonic  of  Bundenbach,  Germany.  It  is 
not  a  common  species. 

Cat.  No.  59380,  U.S.N.M. 

Remarks.—  All  of  the  Bundenbach  material  has  been  subjected  to 
great  pressure  so  that  nearly  all  of  the  finer  details  have  been  obliter- 
ated and  obscured  by  the  adhering  slate.  However,  L.  mirabilis 
can  not  be  confounded  with  any  of  the  associated  species  because  of 
the  constant  absence  of  the  marginal  plates  and  the  smooth  abactinal 
and  interbrachial  membrane.  The  latter  may  have  been  made  up  of 
very  small  calcareous  pieces  now  obliterated  by  the  great  pressure  to 
which  these  fossils  have  been  subjected.  Also  see  Cheiropteraster. 


202  BULLETIN"   88,  UNITED   STATES   NATIONAL   MUSEUM. 

Genus  CHEIROPTERASTER  Sturtz. 

Cheiropteraster  STURTZ,  Palaeontographica,  vol.  36,  1890,  p.  228,  pi.  29,  fig.  33; 
pi.  30,  fig.  32;  Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50, 1893,  pp.  49,  68. 

This  genus  has  its  nearest  relationship  in  Loriolaster,  from  which 
it  differs  in  having  a  far  larger  oral  opening  and  markedly  different 
ambulacral  columns.  These  are  small  plates,  in  shape  like  the 
vertebrae  in  teleost  fishes,  which  alternate  in  adjoining  columns  and 
do  not  closely  adjoin  medially.  Podial  openings  unknown. 

Madreporite  small,  actinally  situated  near  the  mouth. 

Abactinal  and  interbrachial  integument  granular  and  thorny. 

Oral  armature  pieces  small,  described  as  ambulacral. 

GenoTiolotype  and  only  species. — C.  giganteus  Sturtz  (same  citations 
as  above).  This  large  species  is  very  rare  in  the  Lower  Devonic 
roofing  slates  of  Bundenbach,  Germany. 

Cat.  No.  59381,  U.S.N.M. 

SCHOENASTERID^:,  new  family. 

Specialized  Cryptozonia  with  well-developed  interbrachial  arcs. 
Abactinal  area  reticular,  composed  of  numerous  small  plates.  Inter- 
brachial areas  with  distinctly  imbricating  plates.  Oral  armature 
adambulacral.  Adambulacrals  well  developed  in  the  form  of  a  rope 
(hence  the  name,  from  schoinos,  a  rope).  Ambulacral  plates  and 
madreporite  unknown. 

Contains : 

Schcenaster  Meek  and  Worthen. 

Genus  SCHCENASTER  Meek  and  Worthen. 
Plates  32,  33,  35. 

Schcenaster  MEEK  and  WORTHEN,  Proc.  Acad.  Nat.  Sci.  Philadelphia,  vol.  12, 
1860,  p.  449;  Geol.  Surv.  Illinois,  vol.  2,  1866,  p.  277.— ZITTEL,  Handb.  Pal., 
vol.  1,  1879,  p.  453. 

Original  description. — "  Animal  consisting  of  a  flattened  pentagonal 
disk,  with  the  angles  more  or  less  produced  in  the  form  of  rays  or 
arms,  and  the  margins  between  the  rays  concave  in  outline,  and 
fringed  with  short,  flattened,  spine-like  appendages,  which  are  also 
continued  part  of  the  way  out  along  the  lateral  margins  of  the  rays. 
Upper  side  of  rays  composed  of  a  number  of  alternating  solid  plates, 
with  the  dorsal  pores  passing  between  them,  while  the  angles  between 
the  rays  are  filled  with  similar  plates,  forming  the  upper  side  of  the 
disk.  Under  side  of  the  disk  composed  of  numerous  small  plates, 
very  distinctly  imbricating  inward  and  laterally  toward  the  ambu- 
lacra. Ambulacral  furrows  (in  the  typical  species)  wide,  deep,  with 
on  each  side  a  single  row  of  comparatively  stout,  squarish,  or  oblong 
adambulacral  pieces,  having  an  obliquely  outward,  imbricating 
arrangement,  so  as  to  present  somewhat  the  appearance  of  a  twisted 


REVISION   OF   PALEOZOIC    STELLEROIDEA.  203 

cord,  as  seen  from  below ;  farther  out  these  become  the  marginal  pieces 
of  the  free  rays.  There  is;  however,  no  regular  row  of  marginal 
pieces  to  the  disk  between  the  rays.  [In  other  words,  there  are  no 
infra-  or  supramarginals.]  Oral  pieces  ten,  anchylosed  ( ?)  in  pairs,  so 
as  to  look  like  five  pieces  merely  emarginate  at  the  outer  and  inner 
ends.  (Other  characters  unknown.) 

"Of  course  it  is  not  possible  to  give  a  systematic  diagnosis  of  a 
genus  like  this,  of  which  only  imperfect  fossil  species  are  known. 
All  that  can  be  done,  in  cases  of  this  kind,  is  to  give  such  of  the  more 
prominent  characters  as  happen  to  be  visible  in  the  particular  speci- 
mens accessible;  while  we  can  not  always  be  sure,  until  better  speci- 
mens are  obtained,  and  other  species  known,  whether  some  of  the 
characters  given  may  not  be  merely  specific,  or  in  other  cases  of 
more  than  generic  importance.  At  the  same  time,  we  have  to  regret 
our  inability  to  give  any  information  in  regard  to  some  of  the  more 
delicate  parts  that  would  be  the  first  to  claim  the  attention  of  the 
zoologist  in  describing  existing  starfishes. 

"In  first  publishing  a  description  of  the  beautiful  species  forming 
the  type  of  this  genus,  we  referred  it  provisionally  to  McCoy's  genus 
Palasterina,  under  the  subgeneric  name  Schcenaster.  Later  com- 
parisons, however,  have  satisfied  us  that  it  can  not  properly  be  retained 
in  that  genus;  and  as  it  seems  to  present  equally  important  differ- 
ences from  all  the  other  established  genera  known  to  us,  we  now 
propose  to  separate  it  as  a  distinct  genus,  under  the  name  Schoenaster. 
It  is  probably  most  nearly  allied  to  the  Silurian  genus,  Palasterina, 
but  differs  in  the  peculiar  oblique,  outward,  imbricating  character 
of  its  row  of  plates  on  each  side  of  the  ambulacral  furrows,  and  the 
distinct  inward  imbricating  character  of  the  minute,  scale-like  plates 
covering  the  under  side  of  the  disk.  There  are  likewise  differences 
in  the  arrangements  of  the  plates  and  pores  of  the  dorsal  side  of  the 
free  arms,  as  seen  in  our  figure  7&,  pi.  19. 

"As  the  disk  is  not  seen  in  the  specimen  from  which  figure  7d, 
of  the  plate  just  alluded  to,  was  drawn,  it  presents  so  different  an 
appearance  from  fig.  7a  of  the  same  plate,  showing  the  upper  side 
of  the  fossil,  that,  looking  at  these  figures  alone,  doubts  might  arise 
whether  or  not  they  belong  to  the  same  type.  An  examination, 
however,  of  the  upper  side  of  the  same  specimen  from  which  7d  was 
drawn,  as  well  as  of  other  fragments,  shows  them  to  be  the  same.  A 
fragment  of  the  same  specimen  from  which  fig.  Id  was  drawn  also 
shows  portions  of  the  under  side  of  the  disk. 

"Another  species,  apparently  of  this  genus,  from  the  Burlington 
limestone,  with  much  narrower  ambulacral  furrows1,  shows  numerous 

i  "We  should  explain  here,  that  the  ambulacral  furrow  of  the  enlarged  ray,  represented  by  fig.  7c  of 
plate  19,  is  proportionally  too  broad,  in  consequence  of  the  accidental  flattening  of  the  specimen,  and  in 
part  to  the  adambulacral  pieces  being  represented  proportionally  too  small.  These  furrows  are  more 
nearly  natural  in  fig.  7d,  but  even  in  that  specimen  they  are  proportionally  wider  than  in  undistorted 
examples." 


204  BULLETIN"   88,   UNITED   STATES   NATIONAL   MUSEUM. 

little,  short,  flattened,  spine-like  appendages  protruding  from  these 
furrows,  with  an  outward  imbricating  arrangement  or  inclination 
towards  the  extremities  of  the  rays.  There  may  have  been  other 
little  spines  over  the  outer  surface,  in  addition  to  those  fringing  the 
margins  of  the  disk,  though  the  specimens  retain  no  traces  of  them." 

Genoholotype. — S .  fimbriatus  Meek  and  Worthen.  Lower  Carbonif- 
erous (St.  Louis)  of  Illinois. 

The  other  three  species  referred  to  ScTmnaster  probably  do  not  be- 
long in  this  genus.  The  specimens  have  not  been  studied. 

SCHCENASTER  FIMBRIATUS  Meek  and  Worthen. 

Plate  35,  figs.  1-4. 

Palseasterina  (Schoenaster}  fimbriata  MEEK  and  WORTHEN,  Proc.  Acad.  Nat.  Sci., 

Philadelphia,  vol.  12,  1860,  p.  449. 
Schcenaster  fimbriatus  MEEK  and  WORTHEN,  Geol.  Surv.  Illinois,  vol.  2,  1866, 

p.  278,  pi.  19,  figs.  7a-7d. 

Original  description. — "Body  regularly  pentagonal  star-shaped, 
with  the  rays  produced  into  rather  acutely  pointed  arms,  which  are 
convex  above,  and  about  equal  in  length  to  the  diameter  of  the  disk. 
Plates  of  the  upper  side  of  the  arms  and  disk,  convex,  or  even  tumid ; 
near  the  disk  those  of  the  rays  hexagonal,  heptagonal,  or  irregular 
in  form,  alternating,  and  consisting  of  about  five  or  six  longitudinal 
rows,  with  a  few  much  smaller  intermediate  pieces.  Farther  out 
the  rays,  they  gradually  pass  into  two  mesial  ranges  of  oblong,  alter- 
nating pieces,  with  their  longer  diameter  parallel  to  that  of  the  rays; 
while  on  each  side  of  these,  minute  irregular  pieces  fill  the  space 
between  them  and  the  marginal  pieces.  Toward  the  extremities 
of  the  rays,  these  little  intermediate  pieces  diminish  in  size  and  at 
last  become  obsolete,  leaving  only  the  two  middle  and  outer,  or  adam- 
bulacral  rows.  Ambulacral  furrows,  in  apparently  undistorted 
specimens,  deep  and  nearly  or  quite  twice  as  wide  as  the  row  of 
pieces  on  either  side;  adambulacral  pieces  rather  thick  and  strong, 
and  liable  to  present  considerable  differences  in  their  obliquity  and 
breadth  of  surface  exposed,  in  consequence  of  the  compression  or 
distortion  of  the  specimen.  Plates  of  the  under  side  of  the  disk,  very 
much  smaller  than  the  adambulacral,  closely  crowded  together, 
and  owing  to  their  imbricating  arrangement,  presenting  much  the 
appearance  of  the  scales  of  a  fish;  immediately  on  each  side  of  the 
rays,  they  imbricate  toward  the  latter,  but  near  the  middle  of  the 
space  between  any  two  ambulacra,  the  imbrication  is  inward  toward 
the  mouth,  so  that  in  tracing  the  rows  parallel  to  their  longer  diam- 
eter, across  between  the  rays,  they  are  found  to  describe  a  nearly 
semicircular  curve,  with  a  slight  angularity  near  the  middle. 

"Near  the  extremities  of  the  rays,  the  dorsal  pores  are  seen  to 
pass  between  the  ends  of  the  two  mesial  ranges  of  oblong  pieces, 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  205 

but  farther  in  toward  the  disk  they  are  more  irregularly  dis- 
tributed. Our  enlarged  figure  7&,  pi.  19,  represents  these  pores 
and  the  dorsal  plates,  as  seen  in  one  of  the  rays,  with  the  convex 
outer  portion  of  the  plates  ground  away,  in  which  condition  the  pores 
probably  appear  larger  than  natural.  In  specimens  with  the  tumid 
portion  of  these  plates  unremoved,  the  pores  are  not  readily  seen, 
and  the  whole  dorsal  side  then  seems  to  be  made  up  of  solid,  close- 
fitting  pieces.  Greatest  diameter  across  between  the  extremities  of 
the  opposite  rays,  about  2.37  inches;  diameter  of  disk,  1  inch;  breadth 
of  ambulacral  furrows,  about  0.10  inch;  length  of  little  flattened 
marginal  spines,  near  0.08  inch. 

" Locality  and  position. — St.  Clair  County,  Illinois;  in  the  St.  Louis 
division  of  the  Subcarboniferous  series." 

The  specimen  has  not  been  studied. 

SCHCENASTER  (?)  WACHSMUTHI  Meek  and  Worthen. 
Plate  33,  fig.  6. 

Schcenaster  wachsmuthi  MEEK  and  WORTHEN,  Proc.  Acad.  Nat.  Sci.,  Philadelphia, 
vol.  18,  1866,  p.  259;  Geol.  Surv.  Illinois,  vol.  3,  1868,  p.  499,  pi.  17,  fig.  4. 

Original  description. — "Body  flattened  or  much  depressed,  with 
a  regular,  distinctly  pentagonal  outline,  the  angles  being  produced 
into  five  rather  attenuated  rays,  which  are  a  little  convex  above, 
and  apparently  as  much  as  two-thirds  as  long  as  the  diameter  of 
the  disk,  if  not  more.  Disk  concave  in  outline  on  the  margin  be- 
tween the  rays,  and  imparting  a  slightly  alate  character  to  the 
latter  by  extending  a  little  along  their  margins;  like  the  dorsal  side 
of  the  rays,  composed  above  of  numerous  bmall,  slightly  convex 
plates.  Dorsal  pores  moderately  distinct  between  the  plates. 
Plates  of  the  under  side  of  the  disk  about  as  large  as  those  of  the 
dorsal  side,  but  flattened,  scalelike,  crowded,  and  having  the  inward 
imbricating  character  of  the  genus  strongly  marked.  Ambulacra 
(as  seen  in  a  compressed  specimen)  very  narrow,  their  marginal 
plates  moderately  large,  oval-oblong,  comparatively  thin,  and  very 
strongly  imbricating  outward.  Between  these,  two  rows  of  short, 
flattened,  spinelike  scales  are  seen  arising  from  the  ambulacral 
furrow,  and  all  inclining  outward  or  toward  the  extremities  of  the 
rays.  (Other  characters  unknown.) 

"Diameter  of  disk,  1.32  inches;  rays  apparently  extending  as  much 
as  0.90  inch  or  more  beyond  the  margins  of  the  disk. 

"This  species  will  be  readily  distinguished  from  our  8.  fimbriatus, 
of  the  St.  Louis  limestone,  the  only  other  species  of  the  genus  known 
to  us,  by  its  smaller  and  less  convex  plates  on  the  dorsal  side,  as  well 
as  by  its  much  thinner,  less  oblique,  and  more  strongly  imbricating 
row  of  plates  along  each  side  of  the  ambulacra,  and  particularly 
by  its  much  narrower  ambulacral  furrows.  We  have  not  seen  any 


206  BULLETIN 

traces  of  the  row  of  short,  flattened,  marginal  spines  seen  around  the 
disk  of  S.  fimbriatus,  in  the  form  under  consideration;  nor  have 
the  similar  little  appendages  arising  in  a  double  row  from  the  am- 
bulacra of  the  latter  been  seen  in  S.  fimbriatus.  These,  however, 
may  be  rather  generic  than  specific  characters,  and  consequently 
be  found  common  to  both  species. 

"The  specific  name  is  given  in  honor  of  Mr.  Charles  Wachsmuth, 
of  Burlington,  Iowa,  the  discoverer  of  the  only  specimen  we  have 
seen." 

Formation  and  locality. — Burlington  limestone,  Burlington,  Iowa. 
The  specimen  has  not  been  seen;  it  is  in  the  Museum  of  Compara- 
tive Zoology,  Harvard  University  (No.  7). 

SCHCENASTER  (?),  new  species. 

In  the  Gurley  collection  of  the  University  of  Chicago  there  is  a 
small  specimen  (No.  10993)  from  the  Chester  formation  of  Pope 
County,  Illinois.  According  to  the  older  classification  it  would  be 
referred  to  Schwnaster,  but  until  this  genus  is  thoroughly  revised 
nothing  of  generic  value  can  be  done  with  these  Carboniferous 
asterids.  The  specimen  under  discussion  seems  to  be  most  closely 
related  to  S.  (?)  wachsmuthi. 

Measurements:  R  =  about  10  mm.,  r  =  about  3.5  mm. 

SCHCENASTER  (?)  LEGRANDENSIS  Miller  and  Gurley. 

Plate  32,  figs.  4-6. 

Schcenaster  legrandensis  MILLER  and  GURLEY,  Descr.  new  gen.  and  ep.  Echinod., 

1890,  p.  56,  pi.  9,  figs.  7-9.— MILLER,  Sixteenth  Rep.  Geol.  Surv.  Indiana, 

1891,  p.  371,  pi.  9,  figs.  7-9;  N.  Amer.  Geol.  Pal.,  App.  1, 1892,  p.  682,  fig.  1246. 

Original  description. — "Body  thin,  regularly  pentagonal,  sides 
concave,  with  long,  nanow,  gradually  tapering  convex  arms.  Plates 
on  the  dorsal  side  of  the  disk  in  our  specimen  apparently  anchylosed, 
and  spines,  if  any  belonged  to  the  margin,  broken  away.  Ventral 
side  depressed  and  flat  between  the  arm  furrows,  where  it  consists 
of  very  small  plates,  and  if  they  imbricate  inward  the  overlap  must 
be  very  slight.  Ambulacral  furrows  wide,  deep;  two  rows  of  sub- 
quadrangular,  ambulacral  plates  form  the  bottom  of  each  furrow, 
on  each  side  of  which  there  is  a  row  of  oblong  adambulacral  plates, 
having  an  obliquely  inward  imbricating  arrangement,  presenting 
somewhat  the  appearance  of  a  twisted  cord;  these  are  continued  to 
the  ends  of  the  arms  with  the  same  obliquely  inward  imbricating 
arrangement.  Five  pairs  of  oral  plates. 

"This  species  is  small  in  comparison  with  the  two  heretofore 
described,  has  sides  less  convex,  and  narrower  arms." 

Formation  and  locality. — Kinderhook  limestone  at  Le  Grand, 
Iowa.  The  specimen  has  not  been  seen;  it  may  be  in  the  Gurley 
collection  of  the  University  of  Chicago.  It  is  certainly  not  a  form 
of  Schcenaster. 


REVISION   OF   PALEOZOIC   STELLEEOIDEA.  207 

SCHCENASTER  (?)  MONTANUS  Raymond. 

Plate  33,  fig.  5. 

SdiMnaster  f  montanus  RAYMOND,  Ottawa  Naturalist,  vol.  26,  1912,  p.  80,  fig. 
3  on  p.  81. 

Original  description. — "Animal  small,  about  an  inch  in  diameter. 
Rays  short,  slender,  extending  about  one-half  their  length  beyond 
the  disk.  Disk  large,  pentagonal,  the  margin  slightly  concave 
between  the  rays.  The  five  proximal  plates  of  the  adambulacral 
series  function  as  orals,  while  on  the  arms  beyond  the  disk  the  adam- 
bulacrals  become  marginals.  The  adambulacral  plates  are  rather 
small,  oval,  placed  with  the  long  axis  diagonal  to  the  axis  of  the  arm. 
On  the  most  perfect  arm  there  are  16  of  these  plates  on  each  side  of 
the  groove,  not  counting  the  proximal  and  distal  plates. 

"The  ambulacral  ossicles  are  small,  arranged  alternately.  On 
this  specimen  they  are  mostly  displaced.  The  plates  on  the  disk 
between  the  rays  are  few  and  small.  The  marginals  are  small, 
rounded,  and  do  not  appear  to  bear  spines,  but  this  appearance  may 
be  due  to  poor  preservation. 

" Locality. — This  species  is  described  from  a  single  specimen  col- 
lected by  the  writer  in  the  Madison  limestone  at  Spring  Canyon  in 
the  Ruby  Mountains,  near  Alder,  Montana.  The  type  is  in  the 
Carnegie  Museum,  Pittsburgh,  Pennsylvania." 

PAL^EOSOLASTERID^E,  new  family. 

Specialized  multiradiate  Cryptozonia  with  as  many  as  29  rays, 
large  disk,  and  actinal  madreporite.    Ambulacralia  opposite  or  slightly 
alternating. 
Contains : 

Palseosolaster  Stiirtz. 
Echinasterias  Sttirtz. 
Echinodiscaster  Delage  and  Herouard. 
Echinostella  Stiirtz. 
Medusaster  Sttirtz. 

How  rays  are  introduced  in  multi-rayed  asterids. — For  paleontologic 
purposes  it  is  not  necessary  to  go  deeply  into  this  matter,  'but  it  is 
desirable  to  know  when,  where,  and  how  the  supernumerary  rays  are 
introduced  in  living  forms  so  that  we  may  be  guided  in  our  generic 
studies. 

Ritter  and  Crocker1  have  recently  summed  up  what  is  known  on 
this  subject,  and  to  their  paper  the  reader  is  referred  for  further 
study. 

In  nearly  all  cases  the  multi-rayed  forms  have  the  rays  of  equal 
development,  and  for  this  reason  it  is  the  general  belief  that 

i  Ritter  and  Crocker,  Multiplication  of  rays  and  bilateral  symmetry  in  the  20-rayed  starfish,  Pycnopodia 
kelianthoides  (Stimpson),  Proc.  Washington  Acad.  Sci.,  vo  .  2, 1900,  pp.  247-274. 
50601°— Bull.  88—15 14 


208  BULLETIN   88,  UNITED  STATES  NATIONAL  MUSEUM. 

adults  have  the  full  complement  of  rays  characteristic  of  a  species. 
In  some  forms  there  are  individuals  with  smaller  immature  arms, 
but  it  is  not  certain  that  these  are  newly  introduced  rays,  or  that 
"this  disparity  in  size  is  due  to  the  regeneration  of  the  halves  of 
automatically  bisected  animals77  (p.  248).  It  is  true  that  certain 
species  start  with  the  full  complement  of  rays  and  introduce  none 
hi  later  growth.  Others  certainly  deviate  from  this  rule,  and  a 
species  with  as  many  as  37  rays  has  one  small  specimen  with  only 
24  plus  2  young  sprouting  rays.  It  is  therefore  plain  that  "in 
Heliaster  rays  are  added  until  far  in  adult  life,77  and  it  is  also  probable 
that  "they  are  added  in  pairs77  (p.  249).  In  Labidiaster  as  many  as 
six  new  rays  may  bud  simultaneously  at  intervals  around  the  entire 
circumference  of  the  disk. 

An  adult  Pycnopodia  has  from  20  to  24  rays,  and  "this  variation 
does  not  depend  upon  the  size  of  the  specimen.  *  *  *  The 
number  is  generally  even,  *  *  *  but  a  few  specimens  with  21 
have  been  found77  (p.  250).  The  smallest  specimen  had  six  equal 
arms  and  two  much  smaller  budding  rays,  one  larger  than  the  other. 
Between  these  two  extremes  all  intervening  stages  occur.  At  least 
the  original  five  and  probably  six  rays  are  of  larval  origin,  all  the 
others  being  postlarval.  When  the  sixth  ray  is  introduced  is  un- 
known; the  rest  as  a  rule  appear  in  bilateral  order — that  is,  in  pairs. 
They  are  all  developed  "in  a  budding  area  adjacent  to  I  and  II77 
on  the  side  toward  the  sixth  ray  until  late  in  adult  life.  When  the 
arms  are  of  unequal  number  it  is  due  to  the  suppression  of  a  ray. 
In  Pycnopodia,  therefore,  ray  multiplication  goes  on  through  a  con- 
siderable part  of  adult  life,  but  not  the  whole  of  it,  and  is  variable 
with  the  individuals.  All  of  the  rays,  whether  of  larval  or  post- 
larval  origin,  have  the  same  structural  characters. 

Finally,  it  seems  that  the  sixth  ray  in  Pycnopodia  has  its  origin 
in,  or  at  least  "is  in  some  intimate  way  related  with  the  larval  organ 
of  the  embryo77  (p.  268).  Therefore  multiradiation  among  asterids 
has  its  origin  in  late  larval  life. 

In  Heliaster ,  Clarke  states,1  "the  formation  of  new  rays  is  funda- 
mentally different  from  that  in  Pycnopodia."  They  do  not  develop 
hi  distinct  generations,  but  appear  entirely  independently  of  each 
other.  "A  considerable  number  may  develop  at  approximately  the 
same  time,  often  as  many  as  six  or  seven  and  sometimes  eight  or 
nine  in  H.  polybrachius,  but  they  show  no  definite  relation  to  each 
other.77 

The  evidence  seems  "to  show  that  they  tend  to  arise  in  all  four 
quadrants  of  the  circumference  of  the  starfish  about  equally,  but 
successively  rather  than  simultaneously.77 

i  H.  L.  Clarke,  Bull.  Mus.  Comp.  Zo61.,  vol.  51, 1907,  pp.  25-76. 


KEVISION   OF   PALEOZOIC   STELLEROIDEA.  209 

In  Heliaster  the  original  number  is  five,  and  the  new  rays  are  not 
as  a  rule  disposed  bilaterally  (pp.  63-66). 

Verrill  (1914)  states  that  Heliaster  and  allied  living  forms  strikingly 
resemble  Helianfhaster  of  the  Devonic,  "  and  may  indicate  a  con- 
tinuous descent  from  these  ancient  forms'*  (p.  13).  He  also  says,  "I 
am  inclined  to  believe  that  the  increase  in  number  of  rays  has  been 
due  more  to  the  advantage  gained  in  holding  their  food  securely,  and 
in  opening  bivalves,  than  for  holding  to  the  rocks,  though  both  go 
together'7  (p.  16). 

Genus   PALvEOSOLASTER  Sturtz. 
Plate  34. 

Palseosolaster  STURTZ,  Verb.  nat.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56,  1900,  pp. 

226-229,  pi.  2,  figs.  1-3. 
Helianthaster  CLARKE  (part),  Bull.  N.Y.  State  Mus.,  No.  121,  1908,  p.  64,  pi.  11. 

Generic  characters. — Disk  very  large,  with '  27  to  29  rays  in  the 
genotype,  which  project  one-third  their  length  beyond  the  disk. 
Animal  large,  up  to  190  mm.  in  greatest  diameter.  Disk  and  rays 
without  marginalia.  Length  of  rays  95  mm.,  width  of  rays  7  mm. 

Abactinal  area  decidedly  and  abundantly  spinous  and  devoid  of  all 
columns  of  plates. 

Actinally  the  great  disk  is  also  decidedly  spinous.  Rays  slender, 
with  wide  ambulacra;  ambulacral  plates  very  narrow,  seemingly 
alternating,  but  more  probably  opposite,  h-  -shaped,  with  large  podial 
openings  in  two  rows  in  each  ambulacrum.  The  rays  are  bounded 
by  narrow  columns  of  small  adambulacral  ossicles  that  bear  spines 
on  their  outer  sides.  Mouth  circular  and  very  large.  The  nature  of 
the  stout  oral  armature  can  not  be  made  out. 

Madreporite  actinal,  placed  near  the  mouth,  interbrachial,  very 
large,  striate,  more  or  less  oval,  about  34  mm.  in  greatest  width. 

The  general  aspect  is  said  to  be  much  like  the  living  Solaster  affinis 
Brandt. 

GenoJiolotype. — P.  gregoryi  Sturtz  (citations  as  above).  Lower 
Devonic  of  Bundenbach,  Germany.  Another  species  occurs  at  this 
locality  and  a  third  is  found  in  the  Upper  Devonic  of  New  York. 

Remarks. — For  present  purposes  we  may  state  that  Palseosolaster 
has  from  25  to  29  rays  and  that  the  ambulacralia  are  arranged  opposite 
one  another;  the  other  Sturtz  genera,  Echinasterias,  Ec7iinodiscaster} 
and  Echinostella,  are  so  much  like  Paldeosolaster  that  they  may  be 
disregarded. 

Clarke  recently  erroneously  referred  another  very  well  preserved 
species  of  this  genus  to  Helianthaster  (H.  roemeri  Clarke),  but  it 
plainly  has  no  direct  relationship  with  H.  rhenanus.  This  is  seen 
in  the  greater  disk,  larger  number  of  rays,  decidedly  actinal  position 


210  BULLETIN   88,  UNITED   STATES   NATIONAL  MUSEUM. 

of  the  madreporite  and  the  absence  of  interbrachial  inframarginals. 
It  is  clearly  a  Palseosolaster. 

PAL^JOSOLASTER  (?)  GYALUM  (Clarke). 

Plate  34,  fig.  1. 

Helianthaster  gyalum  CLARKE,  Bull.  N.  Y.  State  Mus.,  No.  121,  1908,  p.  63,  pis. 
12,  13. 

Original  description. — The  New  York  specimens,  i  i  Helianthaster 
gyalum  nov.  are  smaller  than  H.  rhenanus.  The  arms  are  more 
numerous  and  appear  to  be  quite  uniformly  24-25.  Compared  to 
H.  rhenanus  they  are  relatively  short,  but  very  long  compared  with 
the  size  of  the  disk,  which  is  much  suppressed,  and  on  none  of  the 
specimens,  all  showing  the  oral  surface,  is  any  distinct  evidence  of 
it  visible,  so  deeply  do  the  arms  cut  into  it  and  so  closely  do  they 
lie  together.  Notwithstanding  this  apparent  retreat  of  the  disk  the 
madreporiform  plate  is  very  large.  This  organ  is  preserved  in  but  one 
example,  but  here  it  overlaps  two  adjoining  interbrachial  angles  and 
the  mouth  parts  pertaining  thereto.  Instead  of  being  a  flat  or 
concave  elongate  plate,  as  in  H.  rhenanus,  it  is  highly  convex  and 
circular;  its  surface  markings  less  distinct  and  coarse  in  that  species. 

"The  great  oral  aperture  is  margined  by  a  series  of  pronounced 
' jaws'  or  sharp  projecting  elevated  angles  the  sides  of  which  take 
origin  from  the  margins  of  adjoining  arms.  These  oral  projections 
are  slightly  expanded  at  their  tips  into  blunt  points  comparable  to 
but  smaller  than  the  'Hocker'  of  H.  rhenanus,  but  like  them  carry 
small  spines  projecting  inward.  The  solidity  and  strength  of  these 
mouth  parts  is  indicated  by  their  prominence  and  elevation  as  shown 
in  figure.  *  *  *  The  reentrant  angle  at  the  base  of  each  arm  is 
narrow,  long,  and  acute,  much  more  extreme  in  these  respects  than 
in  H.  rhenanus  and  very  much  more  elevated." 

Actinally  the  rays  have  two  columns  of  plates  of  which  the  ambu- 
lacrals  are  by  far  the  most  prominent,  are  opposite  one  another  or 
slightly  alternate,  and  occupy  the  comparatively  wide  ambulacral 
furrows.  The  adambulacrals  are  narrow  columns  and  apparently  as 
many  in  number  as  the  ambulacrals.  Laterally  each  adambu- 
lacral  bears  several  spines. 

Locality  and  formation. — A  slab  with  three  individuals  from  the 
Portage  (Upper  Devonic)  at  EaiTs  quarry,  Ithaca,  New  York,  is  now 
in  Cornell  University. 

Remarks. — The  writer  has  not  seen  these  specimens,  but  the  illus- 
trations seem  to  indicate  that  the  " pronounced  jaws"  are  made  up 
of  small  ossicles  of  which  there  are  at  least  five  in  each  column. 
Further,  that  these  ossicles  are  more  probably  the  continuation  of 
the  narrow  adambulacrals  than  of  the  ambulacral  columns  into  the 
great  oral  area,  and  that  proximally  to  these  lie  the  minute  pairs  of 
oral  armature  pieces. 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  211 

The  madreporite  in  P.  (?)  gyalum,  as  in  the  forms  of  Palseosolaster, 
is  very  large,  actinal  in  position,  and  placed  even  closer  to  the  mouth 
than  in  any  other  species.  Not  only  this,  but  it  lies  completely  cov- 
ering one  proximal  ambulacral  furrow  and  across  parts  of  two  adja- 
cent rays.  Its  general  position  and  size  are  in  harmony  with  Palseo- 
solaster  and  not  at  all  with  Helianihaster. 

That  P.  (?)  gyalum  can  not  be  referred  to  Helianihaster  is  therefore 
seen  in  the  different  position  of  the  madreporite,  the  greater  number 
of  rays,  the  wider  ambulacral  furrow,  and  the  improbability  of  its 
having  three  columns  of  abactinal  ray  plates  in  place  of  an  integument 
bristling  with  spines.  All  of  these  differences  are  in  harmony  with 
Palseosolaster.  Further,  if  P.  (?)  gyalum  had  interbrachial  inframar- 
ginals  as  does  Helianihaster,  they  should  show  somewhere  on  these 
five  specimens,  all  of  which  preserve  the  actinal  side.  While  these 
differences  may  not  appear  to  be  great,  they  make  of  Helianihaster  a 
phanerozonian  and  of  Palseosolaster  a  cryptozonian. 

PAL^EOSOLASTER  ROEMERI  (Clarke). 
Heliarthaster  roemeri  CLARKE,  Bull.  N.  Y.  State  Mus.,  No.  121, 1908,  p.  64,  pi.  11. 

From  the  Lower  Devonic  of  Bundenbach,  Germany.  The  holo- 
type  is  in  the  New  York  State  Museum. 

Genus  ECHINASTERIAS  Sturtz. 

Echinasterias  STURTZ,  Verh.  nat.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56,  1900,  p.  230, 
pi.  2,  fig.  4;  pi.  3,  fig.  5. 

The  genotype  has  25  rays,  but  otherwise  appears  to  have  all  the 
generic  characters  of  Palseosolaster. 

Genoholotype  and  only  species. — E.  spinosus  Sturtz  (citations  as 
above) .  Lower  Devonic  of  Bundenbach,  Germany. 

Genus  ECHINODISCASTER  Delage  and  Herouard. 

Echinodiscus  STURTZ  (not  Echinodiscus  Worthen  and  Miller  1883,  Echinoidea), 
Verh.  nat.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56,  1900,  pp.  231-233,  pi.  3,  figs. 
6-10. 

EcMnodiscaster  DELAGE  and  HEROUARD,  Trait6  de  Zoologie  Concrete,  1904. 

Echinodisdtes  SCHUCHERT,  Fossilium  Catalogus,  Animalia,  pt.  3,  1914,  p.  15. 

• 

One  of  the  specimens  has  29  rays  and  a  greatest  diameter  of  160 
mm.  The  writer  fails  to  see  how  this  genus  is  to  be  distinguished 
from  Palseosolaster.  It  may  be  more  abundantly  spinose,  and  the 
madreporite  is  somewhat  smaller  and  more  coarsely  striate,  but  these 
characters  can  hardly  be  of  generic  value. 

Genoholotype  and  only  species. — Echinodiscus  multidactylus  Sturtz 
(citations  as  above).  Lower  Devonic  of  Bundenbach,  Germany. 

Cat.  No.  59386,  U.S.N.M. 


212  BULLETIN   88,  UNITED   STATES   NATIONAL  MUSEUM. 

Genus  ECHINOSTELLA  Sturtz. 

Echinostella  STURTZ,  Verb.  nat.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56,  1900,  pp. 
233-235,  pi.  3,  fig.  11;  pi.  4,  fig.  12. 

The  only  specimen  has  28  or  29  rays  and  a  greatest  diameter  of 
150  mm.  Abactinally  the  rays  and  the  central  area  of  the  disk 
stand  out  rounded  above  the  remainder  of  this  side  of  the  animal, 
which  is  not  the  case  in  Palseosolaster;  otherwise  the  two  genera  aie 
very  much  alike. 

GenoJiolotype  and  only  species. — E.  traquairi  Sturtz  (citations  as 
above).  Lower  Devonic  of  Bundenbach,  Germany. 

Genus  MED  US  ASTER  Sturtz. 

Medusaster  STURTZ,  Palseontographica,  vol.  36,  1890,  p.  229;  pi.  31,  figs.  34,35; 
Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50,  1893,  pp.  54,  73. 

A  form  with  from  12  to  15  rays.  Thought  to  have  relationship 
with  living  Solaster. 

GenoJiolotype  and  only  species. — M.  rhenanus  Sturtz  (citations  as 
above).  Lower  Devonic,  Bundenbach,  Germany. 

Cat.  No.  59385,  U.S.N.M. 

PALEOZOIC  OPHIURIDS. 

A  great  deal  has  been  written  about  these  animals,  but  in  general 
the  true  structure  of  some  of  them  was  not  known  until  very  recently. 
Authors  have  described  these  delicate  and  generally  poorly  pre- 
served fossils  in  such  broad  terms  that  a  complete  restudy  of  all  of 
the  material  is  required  before  it  can  be  said  that  most  of  the  genera 
or  even  the  species  are  established.  The  way  has  been  successfully 
blazed  by  Schondorf  in  Europe,  and  his  methods  of  study  and  results 
need  to  be  applied  to  the  American  fossils.  It  was  the  writer's  hope 
to  do  this,  but  it  is  now  plain  that  his  present  duties  will  prevent  his 
doing  so. 

In  general  it  may  be  said  that  but  few  Paleozoic  so-called  ophiurids 
are  true  Ophiuroidea.  They  are  ophiurid-like  animals,  with  open 
ambulacral  furrows,  but  without  the  essential  characters  of  the 
Asteroidea.  Nor  are  they  transitional  in  structure  between  the 
Asteroidea  and  Ophiuroidea.  Therefore  Schondorf  has  separated 
them  under  the  term  Auluroidea.  It  seems  to  the  writer  that  they 
originated  in  the  Asteroidea  early  in  the  Ordovicic  in  some  crypto- 
zonian  stock  near  Urasterella,  with  large  and  square  ambulacralia. 
(Stenaster  and  Tetraster  are  probably  true  aulurids.)  Out  of  the  Aulu- 
roidea, probably  in  late  Devonic  time,  arose  the  true  Ophiuroidea. 

The  essential  differences  between  the  Auluroidea  and  Ophiuroidea 
will  become  plainer  to  the  student  after  a  study  of  the  text  and 
figures  presented  in  this  work. 


REVISION   OF   PALEOZOIC   STELLEROIDEA. 


213 


Subclass  AULUROIDEA. 

Auluroidea  SCHONDORF,  Palaeontographica,  vol.  67, 1910,  p.  60;  Jahrb.  nassauisch. 

Ver.  Naturk.,  Wiesbaden,  vol.  63, 1910,  pp.  234,  247,  251.— SPENCER,  Mon. 

Brit.  Pal.  Asterozoa,  pt.  1  (Palseontogr.  Soc.  for  1913),  1914,  pp.  24,48.    ' 
Protophiuroidea  and  Euophiuroidea  SOLLAS  and  SOLLAS,  Philos.  Trans.  Roy.  Soc. 

London,  ser.  B,  vol.  202,  1912,  pp.  214,222. 

Auluroidea  are  Paleozoic  brittle-stars,  with  a  more  or  less  well- 
developed  central  disk,  whose  border  between  the  rays  is  more  often 
concave  than  convex ;  in  other  words, 
star-shaped.  The  rays  appear  al- 
ways to  be  five  in  number,  simple, 
long  and  slender,  and  more  or  less 
sharply  marked  off  from  the  disk  as 
appendages.  This  means  that  the 
body  cavity  does  not  extend  from 
the  disk  into  the  rays  as  in  Aster- 
oidea.  On  the  actinal  side  the  rays 
have  open  ambulacral  furrows  with 
the  ambulacralia  never  anchylosed 
into  vertebrae ;  they  are  arranged  in 
two  columns,  the  pieces  of  which 
are  either  alternate  or  opposite  one 
another. 

Original  definition. — "The  ambu- 
lacral water-vascular  system  lies  in 
a  circular  canal  that  is  situated  wholly  within  the  ambulacralia  medi- 
ally between  the  adjoining  columns  of  ossicles.  From  it  diverge  short 
side  branches  that  either  partially  penetrate  the  substance  of  the 

individual  ambulacrals,  or  lie  in  the  suture 
between  adjoining  ambulacrals;  in  either 
case  they  extend  into  the  ventrally  open, 
broad  ambulacral  furrow.  Ambulacrals  free, 
not  coossified,  those  of  adjoining  columns 
either  alternate  or  opposite,  but  always  di- 
rectly opposite  the  adambulacrals.  Ambu- 
lacrals ventrally  composed  of  a  medially 
situated,  internally  concavely  hollo  wed-out 
body,  which,  as  the  plates  of  the  two  columns 
are  normally  united,  forms  the  medial  ambu- 
lacral canal;  and  of  a  lateral  process  extend- 
ing to  the  adambulacrals,  with  depressions 
on  both  sides  of  it  in  the  ventral  surfaces  of 
the  ambulacrals  and  adambulacrals  [see  fig. 
14].  [These  large  lateral  depressions  are  not  podial  openings  through 
or  between  the  plates  as  in  asterids,  but  appear  to  be  cavities  for  the 
ampullae  or  for  these  and  podial  insertions.  Dorsally  the  ambulacrals 


FlG.  12.— A  SECTION  THROUGH  THE  ABM  OF  AN 
ASTEKID,  AFTEK  SCHONDORF.  A ,  AMBULACRA- 
LIA; Ad,  AD  AMBULACRALIA;  Amp,  AMPULLA; 
D,  DORSAL  SKELETON;  F,  PODIA;  ipl,  ACCES- 
SORY OSSICLES;  Mo,  ATTACHMENT  FOR  UPPER 

LONGITUDINAL  MUSCLES;  Mo1,  UPPER  TRANS- 
VERSE MUSCLE ;  Mu,  ATTACHMENT  FOR  LOWER 
LONGITUDINAL  MUSCLE;  Mv>,  LOWER  TRANS- 
VERSE MUSCLE;  Mv,  VERTICAL  MUSCLE ;  Bo, 
UPPER  MARGINALIA;  Ru,  LOWER  MARGINALIA; 

Wr,  RADIAL  WATER- VESSEL. 


FlG.  13.— A  SECTION  THROUGH  THE 
ARM  OF  A  TRUE  OPHIURID,  AFTER 
SCHONDORF.  Bs,  VENTRAL  SHIELD; 

C^CUTIS;  F,  PODIA;  L,  BODY  CAV- 
ITY; N,  NERVE-RING;  oZm,  uZm, 

UPPER  AND  LOWER  INTERMEDIARY 
VERTEBRAL  MUSCLES;  Rs,  DORSAL 

SHIELD;  Ss,  LATERAL  SHIELD;  W, 

VERTEBRA;     Wr,  RADIAL  WATER- 
VESSEL. 


214 


BULLETIN  88,   UNITED   STATES   NATIONAL   MUSEUM. 


Ad. 


FIG.  14.— A  SECTION  THBOUGH  THE  ARM  OF  AN  AULUBID, 
WITH  ALTERNATING  AMBULACEALIA,  AFTEE  SCHON- 
DOEF.  A,  AMBULACEALIA  OF  THE  DOESAL  AND  VEN- 
TRAL SKELETON;  A1,  VENTEAL  EXTENSION  OF  THE 
AMBULACEALIA;  Ad,  AD  AMBULACEALIA  =  LATERAL 

SHIELDS  OF  OPHIUEIDS;  F,  PODIA,  ON  LEFT  THE  CANAL 
PASSES  THBOUGH  THE  PLATE,  ON  EIGHT  THE  PLATE  IS 
DISSECTED  DOWN  TO  THE  CANAL;  Wr,  INTEESKELETAL 
EADIAL  WATEE- VESSEL. 


are  covered  with  spines  and  tubercles.]  Disk  with  concave,  or  con- 
vex ( ?)  margins,  with  or  without  marginal  ossicles.  When  the  latter 
are  present,  they  never  extend  along  the  rays,  but  are  wholly  re- 
stricted to  the  disk.  The  rays  on  both  sides  are  margined  by  the 
adambulacrals.  Ventrally  the  rays  have  broad  open  ambulacral  fur- 
rows, bounded  laterally  by  the 
adambulacrals.  A  typical  mad- 
reporite  [probably  always]  lies 
in  one  of  the  ventral  interradii. 
"The  group  [subclass]  is  re- 
stricted to  the  older  Paleozoic." 
Remarks. — This  subclass  of 
Stelleroidea  appears  to  be  an  in- 
dependent development  whose 
structure  partakes  of  that  of 
the  Asteroidea  and  the  Ophiu- 
roidea,  though  more  like  the 
latter.  The  Auluroidea  agree 
with  the  asterids  in  having  open 
ambulacral  furrows,  and  a  true  madreporite,  which  is,  however,  ven- 
trally  situated,  but  otherwise  the  class  is  more  like  the  ophiurids,  since 
the  body  cavity  does  not  extend  into  the  rays  as  in  true  starfishes. 
However,  the  water-vascular  canal  in  the  Auluroidea  does  not  lie 
outside  of  the  ambulacrals  as  in  the  Asteroidea,  but  within  these 
ossicles  along  the  mid-line  of  the  ambulacrum  in  a  canal  that  is  cut 
out  of  the  sides  of  adjoining  ambulacral  columns.  On  the  other 
hand,  the  Ophiu- 

roidea  have  the  am-          AA  A  A      i*  A4     A    A    Ad 

bulacralia  coossified 
and  modified  into 
vertebral  ossicles; 
there  are  no  open 
ambulacral  furrows, 
and  the  entire  rays 
are  covered  by  four 
columns  of  shields  or  by  an  integument  more  or  less  studded  with 
calcareous  plates  and  granules. 

It  appears  that  the  Auluroidea  all  have  dorsally  four  columns  of 
plates,  of  which  the  two  medial  ones  are  the  most  prominent.  These 
are  undoubtedly  the  dorsal  aspect  of  the  thickened  ambulacrals. 
Outside  of  the  disk  they  are  usually  convex  and  more  or  less  orna- 
mented with  granules,  but  within  the  disk  are  less  prominent  and  take 
on  other  expressions,  commonly  with  concave  surfaces.  The  plates 
outside  of  these  margin  the  rays  and  are  the  adambulacrals;  while 
in  some  forms  they  are  prominent  and  tuberculate,  usually  they  are 
made  up  of  narrow  vertical  pieces  that  bear  spines  along  the  ventral 
or  only  the  distal  ventral  edge. 


FIGS.  15  AND  16.— VENTEAL  AND  DOESAL  AEM  STBUCTUEE  OF  AULUBOIDEA, 
WITH  THE  AMBULACEA  ALTEENATING.  SCHEMATIC,  AFTEE  SCHSNDOEF. 
A,  AMBULACEALIA;  A1,  VENTEAL  EXTENSIONS  OF  AMBULACEALIA;  A 3, 
AD  AMBULACEALIA;  FS,  PODIAL  CAVITIES. 


KEVISION   OF  PALEOZOIC   STELLEKOIDEA.  215 

The  Auluroidea  can  be  divided  into  two  orders  on  the  basis  of 
whether  the  ambulacrals  on  each  side  of  the  median  line  are  arranged 
alternately  (the  Lysophiurae),  or  are  opposite  to  one  another  (the 
Streptophiurae).  The  following  classification  is  a  modification  of 
the  one  offered  by  Gregory  in  1897,  and  kis  work  was  in  turn  a 
modification  of  that  of  Bell  in  1892. 

After  the  present  work  was  written,  its  author  first  became  aware 
of  the  works  of  Sollas  and  Sollas,  and  Spencer.  The  reader  should 
consult  those  papers  for  important  studies  on  the  Auluroidea. 

Order  LYSOPHIUR^E:  Gregory. 

Encrinasterise  BRONN  (part),  Klassen  u.  Ordnungen  d.  Tierreichs,  vol.  1,  1859, 

p.  287. — SCHONDORF,  Palaeontographica,  vol.  57,  1910,  p.  61. 
Ophio-Encrinasterise  STURTZ,  Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56, 

1900,  p.   198.— SCHONDORF,    Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden, 

vol.  63,  1910,  pp.  234,  237. 
Lysophiurse  GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1030  (contains 

Protasteridse  and  Palaeophiuridae) ;  Treat.  Zool.,  vol.  3,  Echinoderma,  1900, 

p.  274. — SOLLAS  and  SOLLAS,  Philos.  Trans.  Roy.  Soc.  London,  ser.  B,  vol. 

202,  1912,  p.  223. 
Ophiurasterix  SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63, 

1910,  p.  251. 

Auluroidea  in  which  the  ambulacral  ossicles  of  adjoining  columns 
are  alternate  to  one  another.  The  individual  plates  are  separate  and 
not  coossified  into  vertebrae. 

Remarks. — The  Lysophiurae  are  Paleozoic  or  primitive  Auluroidea, 
that  is,  ophiurid-like  animals,  with  wide  and  open  ambulacral  furrows 
in  which  the  ambulacralia  are  free  and  alternately  arranged.    The 
ambulacralia  are  common  to  the  actinal  and  abactinal  sides. 
This  order  contains  the  following  families: 

Protasteridse.    Have  boot-shaped  ambulacralia  ventrally. 
Palseophiuridae.   Have  subquadrate  ambulacralia  ventrally. 
Encrinasteridae.     Have    boot-shaped    ambulacralia  ventrally 
and  large  disks  that  are  bordered  by  marginalia. 

Family  PROTASTERIDSE  Miller. 

Protasteridse  MILLER,  N.  Amer.  Geol.  Pal.,  1889,  p.  216.— GREGORY,  Proc.  Zool. 
Soc.  London  for  1896,  1897,  p.  1031;  Treat.  Zool.,  vol.  3,  Echinoderma,  1900, 
p.  274.— PARKS,  Trans.  Canadian  Inst.,  vol.  8,  1908,  p.  366. 

Paldeophiomyxidse  STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56,  1900, 
p.  202. 

"Lysophiurae  with  boot-shaped  ambulacral  ossicles,  each  composed 
of  a  'body '  in  the  median  line  of  the  arm,  and  a  lateral  'wing'  at  right 
angles  to  it"  (Gregory).  There  is  either  a  well-marked  scale-covered 
or  granular  disk,  and  five  flexible  arms.  The  adambulacral  plates  are 
rather  stout,  with  many  lateral  spines. 


216  BULLETIN  88,   UNITED  STATES   NATIONAL   MUSEUM. 

Schondorf  states   that  Gregory's  family  Palseopliiuridae  has   no 
value  and  is  to  be  merged  into  the  one  under  discussion.   The  reasons 
for  this  are  given  beyond  under  the  former  family  heading. 
The  family  contains: 

Tseniaster  Billings.  «  Alepidaster  Meek. 

EopTiiura  Jaekel.  Gregoriura  Chapman. 

Bohemura  Jaekel.  Bundenbachia  Stiirtz. 

Palseura  Jaekel.  PalseopJiiomyxa  Stiirtz. 

Protaster  Forbes. 

Genus  T^ENIASTER  Billings. 
Plate  36,  figs.  1-3. 

Tseniaster  BILLINGS,  Geol.  Surv.  Canada,  Can.  Org.  Rem.,  dec.  3,  1858,  p.  80.— 
CHAPMAN,  Canadian  Journ.,  n.  ser.,  vol.  6,  1861,  p.  517. — WRIGHT,  Mon. 
British  Foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1  (Paleeontogr.  Soc.  for  1861),  1862, 
pp.  24,  34.— HALL,  Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  1868,  p.  300; 
rev.  ed.,  1868=1870,  p.  338.— ZITTEL,  Handb.  Pal.,  vol.  1,  1879,  p.  445.— 
STURTZ,  N.  Jahrb.  fur  Min.,  etc.,  1886,  vol.  2,  p.  150;  Palseontographica,  vol. 
32,  1886,  pp.  78,  83.— MILLER,  N.  Amer.  Geol.  Pal.,  1889,  p.  285.— GREGORY, 
Geol.  Mag.,  dec.  3,  vol.  6,  1889,  p.  26.— STURTZ,  Verh.  naturh.  Ver.  preuss. 
Rheinl.,  etc.,  vol.  50,  1893,  p.  20.— J.  F.  JAMES,  Journ.  Cincinnati  Soc.  Nat. 
Hist.,  vol.  18, 1896,  p.  138.— GREGORY,  Proc.  Zool.  Soc.  London  for  1896, 1897, 
p.  1035;  Treat.  Zool.,  vol.  3,  Echinoderma,  1900,  p.  250.— SPENCER,  Mon. 
Brit.  Pal.  Asterozoa,  pt.  1  (Paleeontogr.  Soc.  for  1913),  1914,  pp.  8,  19. 

Taeniura  GREGORY,  (not  Tseniura  Miiller  and  Heule  1837,  sting-ray),  Proc.  Zool. 
Soc.  London  for  1896,  1897,  p.  1035. 

Original  description  of  Tseniaster. — "  Generic  Characters. — Body 
deeply  stellate;  no  disk  [there  is  a  disk]  or  marginal  plates;  rays 
long,  slender,  flexible,  and  covered  with  small  spines;  two  rows  of 
large  ambulacral  pores;  adambulacral  plates  elongated  and  sloping 
outward  so  that  they  partly  overlap  each  other;  ambulacral  ossicles 
contracted  in  the  middle,  dilated  at  each  end.  Generic  name  from 
tainia,  a  riband." 

Genolectotype  (the  first  species  of  Billings  is  here  selected  as  the 
genolectotype) . — Palxocoma  spinosa  Billings. 

Remarks. — Hall  restudied  the  type-material  of  T&niaster  and 
records  his  observations  as  follows : 

"In  reviewing  the  characters  of  Protaster  and  Eugaster,  I  became 
satisfied  that  there  was  an  intimate  relation  between  these  and 
Tseniaster  of  Billings,  and  in  order  to  satisfy  myself  on  this  point, 
I  have  *  *  *  received  from  Sir  William  E.  Logan,  permission  to 
examine  specimens  of  T&niaster  spinosus  and  T.  cylindricus. 

"An  examination  of  the  specimen  illustrated  in  fig.  3  (ut  sup.) 
reveals  what  I  conceive  to  be  a  disk  not  at  all  unlike  the  disk  of  Prot- 
aster, but  less  extended  than  in  the  Lower  Helderberg  species.  The 
structure  of  the  ray  is  precisely  of  the  same  character  as  the  ray  of 


REVISION   OF  PALEOZOIC   STELLEKOIDEA.  217 

that  species  which  I  have  named  Protaster  forbesi,  the  proportions  of 
plates  and  relations  of  parts  showing  specific  differences/' 

"Mr.  Billings  remarks,  under  the  description  of  T.  spinosus,  that 
'  the  ambulacral  ossicles  appear  in  some  places  to  alternate  with  each 
other,  but  this  is  owing  to  a  distortion;  those  on  one  side  of  the  furrow 
are  opposite  to  those  upon  the  other.7 

"Now  the  specimen  of  this  species  which  I  have  examined,  and 
which  I  suppose  to  be  the  one  figured  upon  Plate  X,  figures  3d,  Z>, 
has  the  ambulacral  plates  alternating  *  *  *. 

"In  the  specimen  of  T.  cylindricus  examined  the  ambulacral 
plates  are  less  distinctly  alternate,  but  the  relation  of  the  adam- 
bulacral  plates  and  the  pores  are  the  same  as  in  the  other  form. 
Not  having  seen  the  specimen  showing  the  dorsal  view,  figure  4o-  of 
plate  X,  I  can  only  remark  that  the  structure  of  the  rays  is  very 
similar  to  that  of  Protaster." 

Without  restudying  the  type-material  of  Tseniaster,  or  paying 
attention  to  Hall's  statements  that  T.  spinosus  has  what  he  con- 
ceived "to  be  a  disk  not  at  all  unlike  the  disk  of  Protaster,"  Gregory 
(1897)  regarded  Tseniaster  as  a  Cryptozonia  starfish  and  made  of 
Billings's  second  species,  T.  cyliiidricus,  a  new  genus,  Tseniura.  The 
latter  he  correctly  refers  to  the  primitive  ophiurids.  Under  these 
circumstances  it  is  desirable  to  repeat  here  what  Gregory  wrote 
about  Tseniaster. 

Tseniaster  "was  described  as  diskless,  which  in  respect  to  the  type 
species  T.  spinosus  is  correct.  In  that  species  the  oral  skeleton 
consists  of  five  pah's  of  large  adambulacrals,  as  in  ordinary  Asterids. 
The  affinities  of  the  true  Tseniaster  appear  to  me  to  be  with  such  forms 
as  Palssaster  ruthveni  [=  Urasterella  ruthveni].  It  is  asteroid  in  the 
oral  armature,  in  its  alternately  arranged  ambulacral  ossicles,  and  in 
the  absence  of  a  disk.  I  therefore  consider  Tseniaster  a  genus  of 
Asteroidea.  The  second  species  placed  by  Billings  in  this  genus 
has,  however,  a  well-marked  disk,  and  has  the  oral  armature  com- 
posed of  five  pairs  of  Ophiuroid  syngnaths.  It  must,  therefore  be 
included  among  the  Ophiuroidea." 

To  adjust  this  matter,  the  writer  restudied  the  genotype  of  Tseniaster 
at  Ottawa  (two  specimens,  No.  1404,  the  originals  of  figures  3a-3d 
of  Billings's  Plate  X).  There  can  be  no  doubt  that  we  have  here  a 
genuine  lysophiurid.  There  is  a  small  disk  present  in  the  individual 
figured  as  3a  and  3Z>,  but  it  is  not  one  with  a  round  outline,  as  in 
typical  ophiurids,  but  is  concave  along  the  margin  between  the  rays. 
Actinally  this  disk  is  abundantly  covered  with  prominent  but  slender 
spines. 

The  ambulacrals  are  distinctly  alternate  throughout  the  rays  and  ap- 
pear as  in  the  sketch  presented  on  page  218;  this  condition  is  not  due 
to  distortion  or  other  causes.  The  side  plates  are  narrow,  and  each 


218  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

bears  three  spines  (see  fig.  17B);  toward  the  mouth  the  two  columns 
diverge  far  more  than  one  would  assume  from  the  original  figure,  and 
in  consequence  there  are  long  and  slender  syngnaths  and  not  the 
asterid-like  mouthpieces  figured  in  the  illustration.  (See  fig.  17C.) 

3 


FIG.  17.— DIAGRAMS  OF  T^NIASTEB  SPINOSUS  (BILLINGS).    A,  To  SHOW  THE  SPINOSE  DISK  WITH  CONCAVE 

SIDES.     B,    ACTINAL  PLATE    ARRANGEMENT:     C,   AMBULACRALS;    ad,   ADAMBULACRALS   OR   SIDE   PLATES, 
WITH  THEIR  SPINES.    C,  MOUTH  PLATES:   a,  AMBULACRALS;   S,  SYNGNATH. 

The  specimen  of  figures  3c  and  3d  is  too  poorly  preserved  to  add 
anything  further.  Associated  with  these  types  there  is  another  and 
much  larger  specimen  with  a  well-marked  disk,  of  which  Billings 
said  nothing  in  his  original  description.  This  form  is  clearly  of 
another  species  (probably  T.  cylindricus) ,  and  is  mentioned  here  so 
that  other  workers  will  not  confound  it  with  the  original  material 
of  T.  spinosus. 

In  1900  Gregory  referred  Tseniaster  to  the  asterid  family  Tsenias 
teridse,  and  placed  here  as  well  the  unrelated  genera  Stenaster,  S  alter- 
aster,  and  Urasterella.  From  what  has  been  stated  above  it  is  plain 
that  T&niaster  can  not  be  closely  related  to  the  cryptozonian  genus 
Urasterella ,  since  the  latter  has  an  abundance  of  narrow  ambulacralia, 
asterid  in  type,  while  these  ossicles  in  the  former  are  far  fewer  in 
number  and  of  the  form  seen  in  other  and  related  Lysophiurse.  It 
is  very  probable  that  Tseniaster  -arose  in  the  same  stock  that  gave 
rise  to  Urasterella  and  Stenaster,  but  the  former  genus  is  clearly  one 
of  the  aulurids. 

In  1896  Gregory  took  out  of  T&niaster  the  second  species  of 
Billings  (T.  cylindricus)  and  based  on  it  the  new  genus  Tseniura. 
As  will  be  seen,  this  name  can  have  no  standing,  as  the  generic  char- 
acters are  those  of  Tseniaster,  and,  further,  the  name  is  preoccupied 
since  1837. 

Thinking  T.  cylindricus  most  closely  related  to  the  primitive 
ophiurids  PalseopTiiura  and  St&rteura,  Gregory  defined  T&niura  as 
follows : 

"Diagnosis:  Palseophiuridse  with  a  small  pentagonal  disk,  not 
bounded  by  marginal  ossicles.  The  ambulacral  furrow  is  broad. 
The  oral  skeleton  is  conspicuous  and  the  syngnaths  each  composed 
of  two  separate  pieces.  The  two  jaws  of  each  oral  angle  are  closely 
attached;  the  mouth  frames  are  separated,  and  each  of  them  is  a 
short,  thick,  slightly  bent  bar." 


REVISION   OF   PALEOZOIC   STELLEEOIDEA.  219 

Genotype  and  only  species. — Palxocoma  cylindrica  Billings. 
11  Remarks:  This  genus  differs  from  PalseopTiiura  by  the  absence 
of  marginal  ossicles  from  the  disk,  and  from  Sturtzura  by  the  smaller 
size  of  the  disk  and  the  form  of  the  syngnaths.  In  Sturtzura  the 
jaws  end  bluntly  against  a  jaw  plate,  whereas  in  Tseniura  they  appear 
to  taper  to  a  point  and  have  no  jaw  plate." 

The  two  cotypes  of  T.  cylindricus  (1405a)  were  lost  for  many  years, 
but  have  recently  been  rediscovered  in  the  collections  at  Ottawa. 
In  addition,  there  is  another  specimen  in  that  Museum  under  this  name, 
and  it  is  probable  that  it  was  so  identified  by  Billings  (No.  1405). 
This  was  the  only  specimen  studied,  and  its  generic  characters  agree 
very  well  with  the  originals  of  the  cotypes  (figs.  4b  and  4c  of  pi.  X), 
and  appear  to  be  in  harmony  with  the  genotype  of  Tseniaster.  The 
only  important  difference  is  that  here  the  ambulacralia  are  directly 
opposite  one  another,  and  not  slightly  alternating,  as  in  T.  spinosus 
(see  fig.  18),  a  difference,  it  seems  to  the  writer,  not  in  itself  alone 
worthy  of  being  the  base  of  a  new  genus  distinct  from  Tseniaster. 
Tseniaster  has  the  following  species: 

T.  spinosu^s  (Billings).     Lower  Trenton. 

T.  cylindricus  (Billings).     Trenton. 

T.  schofiarize  Ruedemann.    Upp^r  Trenton. 

T.  elegans  Miller.     Richmondian  (Waynesville). 

T.  meafoadensis  Foerste.     Richmondian. 

TXENIASTER  SPINOSUS  (Billings). 

Plate  36,  fig.  1;  text  fig.  17. 

Palseocoma  spinosa  BILLINGS,  Geol.  Surv.  Canada,  Rep.  Progress  for  1853-1856, 

1857,  p.  292. 
Tseniaster  spinosus  BILLINGS,  Geol.  Surv.  Canada,  Can.  Org.  Hem.,  dec.  3,  1858, 

p.  81,  pi.  10,  figs.  3a-3d.— MILLER,  N.  Amer.  Geol.  Pal.,  1889,  p.  285,  fig.  439. 

Revised  description  ly  BiUings. — "The  specimens  collected  are 
about  seven  lines  in  diameter;  the  rays  linear-lanceolate,  one  line 
in  width  at  the  base,  and  covered  at  the  sides  with  numerous  small 
spines. 

"In  the  view  of  the  enlarged  specimen  (pi.  X,  3s),  the  ambulacral 
ossicles  appear  in  some  places  to  alternate  with  each,  other,  but  this 
is  owing  to  a  distortion.  Those  on  one  side  of  the  furrow  are  oppo- 
site those  upon  the  other.  The  adambulacral  plates  are  elongated, 
and  so  placed  that  the  outer  extremity  of  the  one  lies  upon  the  inner 
extremity  to  the  next.  The  rays  are  flexible." 

For  remarks  on  this  species,  see  the  discussion  under  Tseniaster. 

Formation  and  locality. — Two  specimens  from  the  Lower  Trenton, 
Falls  of  Montmorency,  east  of  Quebec,  Canada.  The  original  of 
figures  3a  to  3d  is  in  the  Victoria  Memorial  Museum,  Ottawa 
(No.  1404). 


220  BULLETIN  88,   UNITED   STATES   NATIONAL   MUSEUM. 

T^NIASTER  CYLINDRICUS  (Billings). 

Plate  36,  figs.  2,  3;  text  fig.  18. 

Palseocoma  cylindrica  BILLINGS,  Geol.  Surv.  Canada,  Rep.  Progress  for  1853- 
1856,  1857,  p.  292. 

Txniaster  cylindricus  BILLINGS,  Geol.  Surv.  Canada,  Can.  Org.  Rem.,  dec.  3, 
1858,  p.  81,  pi.  10,  figs.  4a-4c. — WRIGHT.  Mon.  British  Foss.  Echinod.,  Oolitic, 
vol.  2,  pt.  1  (Palseontogr.  Soc.  for  1861),  1862,  p.  34.— PARKS,  Trans.  Cana- 
dian Inst.,  vol.  8,  1908,  p.  371. 

Txniura  cylindrica  GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1035. 

Lapworthura  cylindrica  PARKS,  Trans.  Canadian  Inst.,  vol.  8,  1908,  p.  371. 

Original  description. — "One  inch   and   a  half  in  diameter;  rays 
five   [very  flexible],  covered  with   spines,  subcylindrical,  regularly 

rounded  on  the  upper  side,  flattened 
on  the  lower,  about  one  line  in  width 
at  base,  and  regularly  tapering  to  an 
acute  point." 

Formation  and  locality. — In  the  Tren- 
ton limestone  at  Ottawa,  Canada.    The 

. i8.-DiAGRAMOp7cTmAL BAY-PLATES    cotypes    (14050),   along  with   a   third 
OF  TJSKIASTKR  CYLINDKICUS  BILLINGS,    specimen  (1405),  are  in  the  Victoria 

a,  AMBTJLACKAL;  ad,  SIDE  PLATES.  _*  .       ,v, 

Memorial  Museum  at  Ottawa. 

T^ENIASTER  SCHOHARL®  Ruedemann. 

Tseniaster  schoharise  RUEDEMANN,  Bull.  N.  Y.  State  Mus.,  No.  162,  1912,  p.  88, 
pl.  3,  fig.  1. 

Original  description. — The  holotype  "is  small,  the  arms  about  15 
mm.  long,  and  it  is  without  a  disk.  The  arms  are  slender  and  flexible, 
about  1.3  mm.  wide  at  the  base,  and  almost  as  high  in  lateral  view, 
originally  probably  cylindrical.  The  ventral  view  shows  a  straight  or 
slightly  zigzagged  ambulacral  canal,  and  on  both  sides  of  this  squarish 
depressions  surrounded  by  the  ambulacral  and  adambulacral  ossicles, 
the  covering  lower  arm  plates  not  being  retained  if  they  existed. 
The  inner  (ambulacral  or  vertebral)  ossicles  appear  as  narrow  and 
outwardly  curved  ridges,  the  outer  or  adambulacral  ossicles  as  ridges 
bent  in  the  opposite  direction  with  a  projection  in  the  middle  of  the 
outer  arch.  The  ambulacral  ossicles  are  not  directly  opposite  nor 
regularly  alternating,  but  those  of  the  right  side  on  the  ventral  view 
advanced  about  one-third  the  length  of  the  ossicles  beyond  those  of 
the  other  side. 

"The  lateral  view  of  one  other  arm  exhibits  the  ossicles  as  ver- 
tical bars,  that  are  thickened  at  both  ends  resembling  vertebrae 
and  terminating  at  the  dorsal  side  with  a  flat  surface  and  forming 
there  an  apparently  continuous  layer.  They  appear  almost  twice 
as  wide  as  the  intervening  spaces.  The  dorsal  surface  bears  bundles  of 
obliquely  forward  directed  spines,  one  bundle  corresponding  to  each 
ossicle.  These  spines  appear  in  the  right  arm  to  proceed  from 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  221 

small  spine-bearing  plates  attached  to  the  adambulacrals,  as  in  the 
closely  related  Bundenbachia.  On  one  arm  two  bundles  are  seen 
to  proceed  from  each  segment,  one  oblique,  the  other  vertical  to 
the  arm.  The  oral  skeleton  consists  of  stout,  bifid  pieces,  much 
resembling  the  oral  pairs  of  adambulacrals  of  the  genotype." 

Formation  and  locality. — Upper  Schenectady  formation,  the 
eastern  shale  phase  of  the  Upper  Trenton  limestones.  From  near 
Schoharie  Junction,  New  York.  The  holotype  is  in  the  New  York 
State  collection  at  Albany. 

T^ENIASTER  ELEGANS  Miller. 

Tseniaster  elegans  MILLER,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  5,  1882,  p.  41, 
pi.  1,  figs.  6-6c.— J.  F.  JAMES,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  18, 
1896,  p.  139.— PARKS,  Trans.  Canadian  Inst.,  vol.  8, 1908,  pp.  365,  371. 

Protaster  elegans  PARKS,  Trans.  Canadian  Inst.,  vol.  8,  1908,  p.  368. 

Original  description. — "This  species  is  founded  upon  more  than  30 
specimens  occurring  on  a  single  slab,  but  showing  only  the  ventral 
side,  with  the  exception  of  the  ends  of  some  of  the  rays. 

"The  body  is  deeply  stellate,  and  the  rays  long,  slender,  and 
flexible,  and  margined  on  either  side  with  a  row  of  spines. 

"From  the  length  of  some  of  the  rays,  a  complete  specimen, 
properly  spread,  would  probably  have  a  diameter  of  an  inch  and  a 
quarter,  or  more.  The  rays  taper  to  a  sharp  point,  are  rounded  on 
the  dorsal  side,  and  margined  on  the  ventral  side  by  a  row  of  spines, 
one  spine  arising  from  each  plate.  Only  two  rows  of  plates  seem  to 
form  the  dorsal  side  of  a  ray.  The  ventral  side  of  each  ray  is  marked 
by  a  furrow  in  the  middle,  separating  two  series  of  plates  or  ossicles. 
These  plates  are  a  little  longer  in  the  direction  of  the  ray  than  wide, 
and  alternately  break  joints  at  the  middle,  where  they  are  slightly 
contracted." 

Formation  and  locality. — This  extraordinary  slab  is  in  the  Harris 
collection  of  the  United  States  National  Museum.  It  was  found  near 
Waynesville,  Ohio,  in  the  Richmond  formation  of  the  Ordovicic 
period. 

Cat.  No.  40878,  U.S.N.M. 

TffiNIASTER  MEAFORDENSIS  Foerste. 

Txniaster  meafordensis  FOERSTE,  Bull.  Sci.  Lab.  Denison  Univ.,  vol.  17, 1914,  p. 
326,  pi.  4,  figs.  5-7. 

The  reference  to  this  species  is  inserted  as  this  book  is  going  through 
the  press.  The  form  appears  to  be  common  in  the  lowest  Richmon- 
dian  on  Workman  Creek,  three  miles  southeast  of  Meaford,  Ontario, 
Canada.  The  types  are  probably  in  the  Victoria  Memorial  Museum, 
Ottawa,  Canada. 


222 


BULLETIN  88,   UNITED   STATES   NATIONAL   MUSEUM, 


Genus  EOPHIURA  Jaekel. 

Text  figs.  19,  20. 

EopUura  JAEKEL,  Zeits.  geol.  Gesell.,  vol.  55, 1903,  Protokol,  p.  14  (107),  figs.  1,  4. 

GenoJwlotype. — EopMura,  species  not  named.     To  give  this  genus 

proper  standing  according  to  the  rules  of  nomenclature,  the  form  is 

here  named  E.  bohemica,  new  species.     It  is  the  only  species  of  the 

genus,  and  occurs  in  the  Ordovicic  (Dj)  at  Osek,  Bohemia. 

The  genus  is  not  defined  in  the  regular  manner,  but  from  the  general 
discussion  and  the  illustrations  the  following  has  been  made  out: 

Kays  outside  of  the  disk, 
apparently  petaloid  i  n 
form,  with  wide-open  am- 
bulacral  furrows,  having 
narrow  alternating  ambu- 
lacralia  that  are  \ — shaped, 
with  the  podial  openings 
excavated  on  each  side  of 
the  lateral  extensions. 
The  adambulacrals  are 
very  large,  drawn  out  lat- 
erally,rectangular,  lie  hori- 
zontally, and  in  no  way 
resemble  the  side  plates  of 
typical  ophiurids,  or,  for 
that  matter,  even  the  Lys- 
ophiurse.  The  lateral 
edges  of  these  ossicles  are 
slightly  elevated,  tubercu- 
lated,  and  each  bears  about 
four  long  and  very  slender 
spines.  Inside  of  the  disk 
the  adambulacrals  are  nar- 
row and  stand  vertically 
as  in  Paleozoic  ophiurids  ; 
the  columns  first  diverge 
The  two  proximal  pieces  of 
mouth  extensions,  with  the 


FIG.  19.— END  OF  A  KAY  OF  EOPHIUKA  BOHEMICA,  MUCH  EN- 
LARGED, AFTER  JAEKEL.  a,  AMBULACRALIA;  ad,  ADAMBULA- 
CRALIA;  Afg,  PIT  OF  PODIA;  ads,  LATERAL  EXTENSION  OF 
AD  AMBULACRALIA;  Rr,  RADIAL  FURROW;  St,  SPINE  BASES. 


and  then  converge  in  the  mouth  area. 

each  column  make  the  adambulacral 

terminal  ossicles  of  adjacent  columns  side  by  side  but  not  coalesced, 

forming  the  syngnaths.     The  two  most  proximal  ambulacrals  rapidly 

decrease  in  size,  enlarging  the  mouth  area,  with  none  of  these  ossicles 

on  each  side  of  the  two  final  adambulacrals. 

The  disk  seems  to  be  small,  with  concave  interbrachial  sides. 
Actinally  these  areas  are  covered  with  scale  ossicles.  Madreporite 
ventral,  in  the  outer  and  lateral  part  of  an  interradius.  Immediately 
outside  of  the  syngnaths  occur  interradially  two  small  ossicles, 
reminding  one  of  vestigial  inframarginalia. 


REVISION   OF   PALEOZOIC    STELLEROIDEA. 

Genus  BOHEMURA  Jaekel. 
Text  fig*  21. 


223 


Bohemura  JAEKEL,  Zeits.  geol.  Gesell.,  vol.  55,  1903,  Protokol,  p.  18  (111),  fig.  6. 
This  genus,  like  the  foregoing,  is  not  defined  in  the  regulation  way. 
Jaekel's  fine  drawing  shows  that  it  is  closely  related  to  Eophiura, 
differing  mainly  in  that  the  rays  do  not  end  bluntly,  but  have  slowly 
tapering  whip-like  terminations.  These  ends  are  of  course  ontoge- 
netically  young  and  reveal  the  progressive  ray  development.  Here 


FIG.  20.— ORAL  SKELETON  OB-  EOPHIUEA  BOHEMICA,  AFTER  JAEKEL.    a,  AMBULACRALIA;  ad,  ADAMBU- 
LACRALIA;  Ma,  MADREPORITE  AMONG  THE  SCALE  PLATES. 

the  rays  are  made  up  of  overlapping  and  alternating  adambulacrals 
that  distally  have  no  ambulacral  grooves.  Gradually  an  ambulacral 
groove  is  developed  and  it  becomes  rapidly  wider  as  one  examines 
the  rays  more  and  more  proximally,  and  the  adambulacrals  turn 
over  and  flatten  out,  finally  making  the  great  open  ambulacral 
furrows.  The  illustration  here  reproduced,  figure  21  on  page  224, 
will  show  the  generic  characters  as  drawn  by  Jaekel. 

Oenoholotype  and  only  species. — B.  jahni  Jaekel.  Ordovicic  (DJ 
at  Zahorzan,  Bohemia. 

Genus  PALvEURA  Jaekel. 

Text  fig.  22. 
Palseura  JAEKEL,  Zeits.  geol.  Gesell.,  vol.  55, 1903,Protokol,p.l6(109)-17(110),fig.  5. 

Oenoholotype. — Palseura,  species  not  named.  No  species  is  again 
mentioned,  nor  is  it  stated  that  the  generic  name  is  new.  To  give 
the  name  standing,  the  form  figured  is  here  named  P.  neglecta,  new 
genus,  new  species.  It  occurs  in  the  Ordovicic  (Dt)  of  Bohemia; 
the  exact  locality  is  not  given,  but  may  be  Osek. 

50601°— Bull.  88 — 15 15 


224  BULLETIN  88,   UNITED  STATES  NATIONAL   MUSEUM. 


Jaekel  here  again  fails  to  diagnose  his  genus,  but  some  of  the 
characters  can  be  clearly  made  out  from  his  excellent  drawing. 
The  disk  is  small  and  tends  to  have  convex  interbrachial  areas.  So 
far  as  the  oral  disk  area  is  concerned,  the  general  structure  is  that 
of  Eophiura,  with  this  marked  difference — the  opposite  and  asterid- 
like  ambulacralia  of  the  rays  do  not  vanish  proximally  as  in  that 

genus  but  crowd  over  and  finally 
rest  wholly  upon  the  adambulacrals, 
and  end  against  the  distal  edges  of 
the  syngnaths .  These  are  made  up 
of  the  coossified  terminal  adambu- 
lacral  ossicles. 

Genus  PROTASTER  Forbes. 
Text  fig.  23. 

Protester  FORBES,  Mem.  Geol.  Surv. 
United  Kingdom,  dec.  1,  1849,  pi. 
4,  pp.  1-2;  in  McCor,  British  Pal. 
Foss.,  1851,  p.  60.— MURCHISON, 
Siluria,  1854,  p.  221,  fig.  39-4.— 
SALTER,  Rep.  Twenty-sixth  Meet., 
Brit.  Assoc.  Adv.  Sci.,  Notices  and 
abstracts,  1857,  p.  76;  Ann.  Mag. 
Nat.  Hist.,  ser.  2,  vol.  20, 1857,  pp. 
325,  330— HALL,  Nat.  Hist.  N.  Y., 
Pal.,  vol.  3, 1859,  p.  134.— SALTER, 
Ann.  Mag.  Nat.  Hist.,  ser.  3,  vol.  8, 

1861,  p.  484.— WRIGHT,  Mon.  Brit- 
ish Foss.  Echinod.,  Oolitic,  vol.  2, 
pt.  1  (Palseontogr.  Soc.  for  1861), 

1862,  pp.  23, 31.— HALL,  Twentieth 
Rep.  N.  Y.  State  Cab.  Nat.  Hist., 
1868,  p.  293;  rev.  ed.,  1868=1870, 
p.  335. — QUENSTEDT,  Petrefacten- 
kunde  Deutschlands,  vol.  4,  1876, 
p.  133,  pi.  95,  fig.  11.— STURTZ,  N. 
Jahrb.  fiir  Min.,  etc.,  1886,  vol.  2, 
pp.   148,  150.  — GREGORY,   Geol. 
Mag.,  dec.  3,  vol.  6,  1889,  p.  26.— 
ST^RTZ,  Verh.  naturh.  Ver.  preuss. 
Rheinl.,  etc.,  vol.  50, 1893,  p.  18.— 
J.  F.  JAMES,  Journ.  Cincinnati  Soc. 

Nat.  Hist.,  vol.  18, 1896,  p.  137.— GREGORY,  Proc.  Zool.  Soc.  London  for  1896, 
1897,  p.  1031,  fig.  1.— WHIDBORNE,  Palseontogr.  Soc.,  1898,  p.  206.— PARKS, 
Trans.  Canadian  Inst.,  vol.  8,  1908,  pp.  363,  366.— SCHONDORF,  Jahrb.  nas- 
sauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63,  1910,  p.  238. — SOLLAS  and  SOLLAS, 
PMlos.  Trans.  Roy.  Soc.  London,  ser.  B,  vol.  202,  1912,  p.  223.— SPENCER, 
Mon.  Brit.  Pal.  Asterozoa,  pt.  1  (Palseontogr.  Soc.  for  1913),  1914,  p.  35. 

Encrinaster  (part)  HAECKEL,  Gen.  Morphologie,  vol.  2, 1866,  p.  Ixvii  (no  definition). 

Also  Bee  Sturtzura. 


FiG.21.— VENTRAL  VIEW  OF  A  RAY  OF  BOHEMURA 

JAHNI,  ENLARGED  ABOUT    X   2,  AFTER  JAEKEL. 

a,  AMBULACRALIA;  ad,  AD  AMBULACRALIA  WITH 

THEIR  LATERAL  EXTENSIONS;  ddm,  SYNGNATHS. 


REVISION   OF  PALEOZOIC   STELLEBOIDEA. 


225 


Original  description. — "  (Order  Ophiuridse.  Family  Euryales.) 
Body  circular,  covered  with  squamiform  plates;  genital  openings 
in  the  angles  of  junction  of  the  arms  beneath;  arms  (simple)  formed 
of  alternating  ossicula." 

Genoholotype. — " Species  Unica.     Protaster  sedgwickii.     Forbes." 

Original  description  of  P.  sedgwickii. — "The  disk  is  circular,  and 
shaped  like  that  of  an  OpTiiura.  The  arms  are  five  in  number,  very 
narrow,  equidistant,  and  similar. 

"The  upper  and  under  surfaces  of  the  disk  were  covered  by  small, 
similar,  more  or  less  regular,  polygonal  or  crescentic  plates,  imbri- 
cated in  scale-fashion,  and  having  punctated  surfaces.  Those  of 
the  under  side  of  the 
body  are  smaller  and 
more  regular  than 
those  of  the  upper. 
The  mouth  is  cen- 
tral, and  rather  small 
in  proportion  to  the 
disk.  The  buccal  ap- 
paratus is  composed 
of  ten  parts  or  proc- 
esses, arranged  in 
pairs;  half  of  each 
springs  from  the 
origin  of  each  arm  in 
a  diverging  manner, 
and  meets  the  corre- 
sponding half  to  form 
a  lanceolate  tooth- 

1  i  lr  <*     rkrrn'antirkn       FlG>  22.— ORAL  SKELETON  OF  PAI^EUBA  NEGLECTA,  MUCH  ENLARGED, 

u  j  t?         i  o  II,  AFTER  JAEKEL>    at  AMBULACBALIA;  ad,  ADAMBULACEALIA. 

deeply  indenting  the 

cavity  of  the  mouth.  Of  how  many  separate  ossicles  each  of  the 
buccal  processes  was  composed  the  specimen  affords  but  very  indis- 
tinct indication.  They  seem  to  affect  a  slightly  falcate  form  at  their 
extremities.  The  arms  were  composed  of  alternating,  somewhat 
quadrate  ossicula,  the  sides  of  which  were  deeply  indented  supe- 
riorly, in  order  to  form  spiniferous  crests.  The  spines  were  appar- 
ently short,  and  not  equal  in  length  to  the  length  of  an  ossicle,  obtuse, 
and  few  in  a  row.  The  under  surfaces  of  the  brachial  ossicula  were 
not  indented  laterally.  The  central  portions  of  the  upper  surfaces 
of  the  brachial  ossicles  were  hollowed  out  slightly,  and  the  sutures 
between  them  deeply  impressed.  About  12  of  the  brachial  ossicles 
were  imbedded  in  the  disk,  and  the  parts  of  the  dorsal  surface  of 
the  latter,  corresponding  to  the  arms  and  central  skeleton,  do  not 
present  traces  of  scales,  a  feature  seen  in  existing  Euryales. 


226  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

"The  dimensions  of  Prof.  Sedgwick's  specimens  are  as  follows: 
"Breadth  of  disk,  0  8/12ths  inch. 
"Average  breadth  between  arms,  0  5/12ths  inch.     Breadth  of 

an  arm,  at  its  junction  with  the  body,  0  1/1 2th  inch. 
"Locality  and,  geological  horizon. — Silurian,   from  Ludlow  rocks 
at  Docker  Park,  near  Kendal,  Westmoreland   (specimen  figured), 
associated  with  Encrinites,  and  at  Benson  Knot,  also  near  Kendal, 
hi  hard  sandstones,  full  of  characteristic  Ludlow  fossils." 

Gregory  restudied  this  genus  and  in  1897  defined  it  as  follows: 

"Protasteridse  with  a  well-marked  disk;  long,  tapering,  very  flexible 

arms.     Some  of  the  adambulacral  ossicles  are  Y-shaped.     Scales  of 

the  disk  fairly  large.     Type  species. — Protaster  sedgwickii,  Forbes." 

Gregory  remarks  that  "Forbes's  figures  of  the  arm-structures  are 

not   satisfactory," 


figure  23  as  drawn 
by    the   former. 
This      illustration 
a  b  °  shows  each  set  of 


FIG.  23.—  AMBULACHALIA  AND  ADAMBULACRALIA  OF  PROTASTEB  SEDGWICKII, 
AFTER  GREGORY,    a,  NEAR  THE  DISTAL  END;  6,  IN  THE  MIDDLE;  c,  AT     ambulacralia     dif- 

THE  PROXIMAL  END.     THESE  DIFFERENCES  ARE  DUE  TO  PRESERVATION. 


tion  thought  to  be  due  to  preservation  and  adhering  rock  rather  than 
to  structure  (see  fig.  28,  on  p.  242). 

Madreporite  probably  abactinal  in  position. 

In  regard  to  the  term  Encrinaster,  see  Encrinaster  (Aspidosoma)  , 
page  242. 
Protaster  has  the  following  species  : 

P.  sedgwickii  Forbes.     Ludlow  of  England. 
P.  biforis  Gregory.     Wenlock  of  Wales. 
P.  groomi  Sollas  and  Sollas.     Ordovicic  of  England. 
'  P.  (?)  whiteavesianus  Parks.     Black  River. 

P.  (t)  salteri  (Salter).     Ordovicic  of  Wales. 
.    P.  (?)  stellifer  Ringueberg.     Rochester. 

PROTASTER    BIFORIS    Gregory. 

Text  figs.  24,  25. 

Protaster  biforis  GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1032,  figs. 
2,  3  on  p.  1033.  —  SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden, 
vol.  63,  1910,  p.  238. 

Original  description.  —  "Disk  fairly  large;  interbrachial  outlines 
concave.  The  syngnaths  are  simple,  prominent,  and  stout.  The 
ambulacral  ossicles  consist  of  a  thick  body  and  a  stout  curved  wing. 
The  distal  margin  of  the  ossicles  is  notched  by  a  depression  for  a 
ventral  muscle-field,  which  also  cuts  into  the  proximal  margin  of  the 
adjoining  ossicle.  Owing  to  these  muscular  depressions  the  arm  has 
apparently  two  series  of  pores. 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  227 

"The  adambulacral  ossicles  are  massive  and  taper  slightly  to  their 
distal  ends;  they  are  closely  attached  and  form  a  regular  series  of 
marginal  plates. 

"Arms  very  flexible. 

"Dimensions: 

Length  of  longest  arm 18     mm.+a; 

Diameter  of  arm  at  the  base 2.5  mm. 

Diameter  of  arm  near  the  distal  end 1     mm. 

Diameter  of  mouth 1.5  mm. 

Length  of  syngnath 1     mm. 

Width  of  ambulacral  furrow  at  edge  of  disk 1.25  mm. 

"Distribution. — Wenlock  Shale,  Castell  Dinas,  Bran,  near  Llan- 
gollen,"  Wales.  Museum  Practical  Geology,  London. 


if 


24  25 

FIGS.  24  AND  25.—  PROTASTER  BIFOEIS.   AFTEE  GEEGOEY.    24,  AMBULACRALIA  AND  ADAMBULACEAUA. 
25,  O,  OUTLINE  OF  THE  DISK  AND  AEMS;  6,  A  PAIE  OF  SYNGNATHS. 

PROTASTER  GROOMI  Sollas  and  Sollas. 

Protaster  groomi  SOLLAS  and  SOLLAS,  Philos.  Trans.  Roy.  Soc.  London,  ser.   B 

vol.  202,  1912,  pp.  223,  224. 
Occurs  in  the  Middle  Ordovicic  of  Shropshire,  England. 

PROTASTER  (?)  WHITEAVESIANUS  Parks. 

Protaster  whiteavesianus  PARKS,  Trans.  Canadian  Inst.,    vol.  8,    1908,  p.  368, 

figs.  1-6. 

This  is  a  large  form  with  a,  disk  15  mm.  across  and  with  rays  60  mm. 
long.  It  is  described  in  too  much  detail  to  quote  here.  The  ambula- 
cralia  are  distinctly  alternate  and  boot-shaped. 

Formation  and  locality.  —  In  the  Lower  Trenton  (Kirkfield),  at 
Kirkfield,  Ontario,  Canada.  The  cotypes  (five)  are  in  the  University 
of  Toronto  (No.  638  T.). 

PROTASTER  (?)  SALTERI  (Salter). 

Ophiura  salteri  SALTER  and   SOWERBY,  Quart.  Journ.  Geol.  Soc.  London,  vol.  1. 

1845,  pp.  9,  20  (table)  (nomen  nudum). 
Protaster  salteri  WRIGHT,  Mon.  British  foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1  (Pala>on- 

togr.  Soc.  for  1861),  1862,  p.  33  (nomen  nudum).  —  SALTER,  Mem.  Geol.  Surv. 

Great  Britain,  vol.  3,  1866,  p.  289,  pi.  23,  fig.  3  (is  inclined  to  refer  it  to 

Tseniaster}.—  PARKS,  Trans.  Canadian  Inst.,  vol.  8,  1908,  pp.  364,  367. 

Formation  and  locality.  —  The  holotype  is  from  the  Ordovicic,  near 
Cerrig-y-Druidion  on  the  Holyhead  road,  Wales. 


228  BULLETIN  88,  UNITED  STATES  NATIONAL   MUSEUM. 

PROTASTER  (?)  STELLIFER  Ringueberg. 

Protaster  stellifer  RINGUEBERG,  Bull.  Buffalo  Soc.  Nat.  Sci.,  vol.  5, 1886,  p.  7,  pi.  1, 
fig.  2. 

Generic  relations  not  established. 

Original  description. — "Disk  of  medium  size,  flat,  circular,  slightly 
flexible,  distinct  from  the  rays  on  the  dorsal  side,  and  has  on  that 
side  a  quinque-dentate,  stellate,  central  elevation,  which  again  has 
a  central,  stellate  depression  of  about  one-half  the  lateral  extension 
of  the  stellate  elevation  upon  which  it  is  impressed.  The  points  of 
the  star-like  figure  are  opposite  the  several  rays  and  extend  about 
two-thirds  across  the  disk. 

"Surface  finely  granulose.  Rays  slender,  almost  imperceptibly 
tapering  in  the  upper  half  of  their  known  length;  rounding  on  the 
dorsal  side,  with  two  rows  of  regular,  quadrilateral,  alternating 
[ambulacral]  plates  which  can  with  difficulty  be  made  out,  and  which 
have  a  fine  granulose  [integumentary]  surface  resembling  the  surface 
of  the  disk;  opposite  each  transverse  suture  there  is  a  corresponding 
linear  depression  across  the  surface  of  the  opposite  plate  on  the  other 
side  of  the  median  suture,  which  at  first  sight  gives  the  impression 
that  the  ray  is  composed  of  opposite  plates  of  only  one-half  the  real 
length. 

"Ventral  side  with  ten  short,  oral  plates  which  are  slightly  sepa- 
rated below,  and  meet  at  the  discal  surface,  where  they  are  rounded. 

"Ambulacral  series  long,  regularly  quadrilateral;  alternately 
arranged. 

"Adambulacrals  indistinct  in  the  only  specimens  found  showing 
the  ventral  surface. 

"Marginal  series  slightly  imbricating;  spiniferous;  spines  rather 
short." 

Formation  and  locality. — Three  specimens  were  collected  in  the 
Rochester  shale  of  the  Siluric  at  Lockport,  New  York.  They  are  in 
the  author's  collection.  Two  other  fine  specimens  were  found  by  C. 
J.  Sarle  at  Lockport  and  are  now  at  Yale  University.  Another  good 
specimen  is  in  the  Walker  collection  of  the  University  of  Toronto 
(No.  1007) ;  it  was  found  at  Grimsby,  Ontario. 

Genus  ALEPIDASTER  Meek. 
Plate  36,  fig.  4;  text  fig.  26. 

AlepidasterM-EEK,  Amer.  Journ.  Sci.,  ser.  3,  vol.  4,  1872,  p.  275;  Geol.  Surv.  Ohio, 

Pal.,  vol.  1,  1873,  p.  68,  at  end  of  specific  description. 
Protasterina  ULRICH,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  1,  1878,  p.  95. — J.  F. 

JAMES,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  18,  1896,  p.  139  (genoholotype, 

P.  fimbriata  Ulrich). 

Original  description. — "The  only  specimen  I  have  seen  that  is 
certainly  known  to  belong  to  this  species  [P.  ?  granuliferus]  is  very 


REVISION   OF  PALEOZOIC   STELLEROIDEA. 


imperfect,  being  merely  an  incomplete  disk,  and  the  inner  ends  of  the 
rays.  It  does  not  conform  to  the  characters  of  Protaster  given  in 
Prof.  Forbes' s  diagnosis,  in  all  respects,  since  its  disk,  especially  on 
the  upper  side,  is  covered  by  an  integument  composed  of  a  vast 
number  of  very  minute  grains  of  calcareous  matter,  instead  of  dis- 
tinct imbricating  scales.  It  is  therefore  not  improbable  that  perfect 
specimens  would  show  other  characters  that  would  warrant  the 
establishment  of  a  new  genus  or  subgenus  for  such  forms,  in  which 
case  the  name  Alepidaster  might  be  applied  to  the  group." 

Genoholotype. — Protaster  (?)  granuliferus  Meek. 

Original  description  of 
Protasterina. — "Rays  five, 
slender,  flexible,  and  ex- 
tending much  beyond  a  cir- 
cular and  minutely  granu- 
lar disk,  which  is  provided 
with  short,  slender,  and 
outwardly  directed  spines; 
inner  ray  pieces  [ambu- 
lacra] regularly  alternating, 
of  an  hour-glass  shape,  and 
interlocking  along  the  me- 
dian line,  which  is  there- 
fore not  straight  but  zig- 
zag ;  outer  ray  pieces  elon- 
gated [adambulacrals  or 
side  plates],  directed  ob- 
liquely outwards,  so  as  to 
partly  overlap  each  other; 
two  rows  of  large  pores  between  the  inner  [ambulacral]  and  outer 
[side  plates]  ray  pieces;  in  the  type-species  these  pores  appear  to  have 
been  occupied  by  loosely-fitting  subpyramidal  plates,  some  of  which 
have  a  deep  depression  in  the  top,  as  though  they  were  perforated; 
their1  true  nature,  however,  is  very  uncertain.  Oral  pieces  ten,  each 
pair  being  formed  by  two  of  the  outer  ray  pieces.  Type,  P.  fimbriata." 

When  the  original  material  of  Alepidaster  and  Protasterina  is  re- 
studied,  it  may  be  shown  that  the  latter  is  not  a  synonym  of  the 
former,  but  at  present  the  writer  does  not  see  any  generic  differences. 

Alepidaster  is  easily  distinguished  from  Protaster,  not  only  by  its 
greater  geologic  age,  but  also  in  that  its  disk  is  minutely  granular 
and  spiniferous  while  that  of  the  latter  is  scale-bearing.  Further, 
when  the  exact  shape  of  the  ambulacrals  is  determined,  it  is  probable 
that  other  differences  'will  be  found  there.  Particular  attention 
should  be  paid  to  Ulrich's  statement  that  in  Protasterina  the  podial 
openings  "  appear  to  have  been  occupied  by  loosely  fitting,  sub- 


FIG.  26.— DIAGRAMS  OF  ALEPIDASTER  GRANULIFERTJS  (MEEK). 
DRAWN  BY  E.  O.  ULRICH  FROM  A  SPECIMEN  IN  THE  UNITED 
STATES  NATIONAL  MUSEUM.  A,  ACTINAL  VIEW  OF  RAY 
PLATES.  B,  SAME  FROM  ABACTINAL  SIDE.  C,  SECTION 

THROUGH   RAY.     D,  SlDE-PLATE    FROM    THE   INSIDE   AND   IN 

SECTION. 


230  BULLETIN   88,   UNITED   STATES   NATIONAL    MUSEUM. 

pyramidal  plates/'  If  these  extra  plates  existed,  Protasterina  will 
be  a  good  genus,  differing  not  only  from  Protaster,  but  also  from 
Alepidaster. 

Apparently  no  one  has  actually  seen  the  abactinal  side  of  the  rays. 
The  writer  also  fails  to  see  it  in  the  few  specimens  studied.     It  would, 
therefore,  seem  that  there  are  no  dorsal  plates  and  that  the  dorsal 
covering  is  integumentary  or  finely  granular. 
This  genus  contains  the  folio  whig  species : 

A.  (?),  new  species.     Trenton. 

A.  granuliferus  (Meek).     Bichmondian. 

A.flexuosus  (Miller  and  Dyer).     Eden  and  Maysville. 

A.  miamiensis  (Miller).     Bichmondian  (Waynesville) . 

ALEPIDASTER  (?),  new  species. 

In  the  Walcott  collection  at  Harvard  University  there  are  three 
specimens  (Nos.  28,  29,  30)  of  a  "Protaster"  that  probably  will  prove 
to  be  new.  They  are  from  the  Trenton  limestone  at  Trenton  Falls, 
New  York. 

ALEPIDASTER  GRANULIFERUS  (Meek). 
Text  fig.  26. 

Protaster  ?  granuliferus  (Alepidaster  at  end  of  description)  MEEK,  Amer.  Journ. 
Sci.,  ser.  3,  vol.  4,  1872,  p.  274;  Geol.  Surv.  Ohio,  Pal.,  vol.  1,  1873,  p.  68, 
pi.  3  bis,  figs.  8a,  86.— J.  F.  JAMES,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  18, 
1896,  p.  138.— PARKS,  Trans.  Canadian  Inst.,  vol.  8,  1908,  p.  368. 

Original  description. — "Disk  small,  apparently  circular;  rays  rather 
slender,  and  of  unknown  length.  Dorsal  surface  of  disk  and  rays 
covered  by  an  integument  composed  of  innumerable  minute  grains 
of  calcareous  matter.  Ventral  side  of  disk  not  well  exposed  in  the 
specimen  but  apparently  provided,  in  the  interradial  spaces,  with 
minute  spines  directed  outward.  Oral  pieces  not  well  exposed  in 
the  specimen.  Arm  pieces  [ambulacrals]  regularly  alternating,  but 
apparently  rectangular  at  their  inner  ends,  and  not  interlocking  along 
the  minute  mesial  impressed  line,  longer  transversely  than  in  the 
direction  of  the  length  of  the  rays;  each  largely  excavated  at  its 
anterior  outer  end  so  as  to  form  a  large  pore,  or  porelike  depression, 
and  divided  transversely  by  a  furrow  into  two  parts,  the  anterior  of 
which  is  very  short,  and  the  posterior  longer,  and  marked  by  a  minute 
[muscle]  pit  at  its  inner  end;  about  eight  or  nine  of  these  pieces  in 
each  range  of  each  ray  included  within  the  margin  of  the  disk.  Outer 
arm  [or  ray]  pieces  (adambulacral  of  some)  smaller  than  those  of  the 
the  inner  ranges,  and  placed  edge  upward,  with  an  oblique  outward 
direction  so  as  to  imbricate  outward  or  toward  the  extremities  of 
the  rays,  each  bearing  one  or  more  minute  articulating  spines. 

" Breadth  of  disk,  about  0.43  inch;  breadth  of  arms  at  their  inner 
ends,  0.10  inch." 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  231 

Formation  and  locality. — In  the  lower  part  of  the  Richmondian  at 
Moore's  Hill,  Indiana.  It  was  found  by  C.  B.  Dyer,  and  is  now  in 
the  Museum  of  Comparative  Zoology,  Harvard  University  (No.  21). 

ALEPIDASTER  FLEXUOSUS  (Miller  and  Dyer). 
Plate  36,  fig.  4. 

Protaster  flexuosus  MILLER  and  DYER,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  1, 
1878,  p.  31,  pi.  2,  figs.  1,  la.— MILLER,  N.  Amer.  Geol.  Pal.,  1889,  p.  276, 
fig.  409.— PARKS,  Trans.  Canadian  Inst.,  vol.  8,  1908,  p.  368. 

Protasterina  ("Protaster"  lapsus)  fimbriata  ULRICH,  Journ.  Cincinnati  Soc.  Nat. 
Hist.,  vol.  1,  1878,  p.  95,  pi.  4,  figs.  9-9c. 

Protasterina  flexuosa  and  P.  fimbriata  J.  F.  JAMES,  Journ.  Cincinnati  Soc.  Nat. 
Hist.,  vol.  18,  1896,  pp.  139,  140. 

Original  description  of  P.  flexuosus. — "  The  disk  is  composed  of  very 
thin,  small  plates,  the  order  of  arrangement  of  which  is  not  deter- 
mined. The  specimens  examined  differ  in  size,  and  show  the  disk 
varying  in  diameter  from  one-quarter  to  one-half  an  inch.  The  rays 
were  very  flexuous  when  living,  and  are  found  winding  and  turning 
and  thrown  in  different  directions  in  different  specimens. 

"Four  series  of  plates  are  seen  upon  the  dorsal  side  of  each  ray 
near  the  disk.  The  two  inner  series  [the  ambulacrals  seen  from  the 
dorsal  side]  form  an  angular  ridge,  each  plate  is  concave  at  the  uniting 
surface,  the  arrangement  is  alternate,  and  the  appearance,  therefore, 
of  the  top  of  the  ray,  is  something  like  the  alternate  arrangement  of 
two  series  of  hourglasses.  The  outer  series,  or  marginal  [side]  plates, 
are  spinous,  the  spines  directed  toward  the  point  of  the  ray.  A 
weathered  ray  shows  three  series  of  pores — one  row  between  the  inner 
series  of  plates,  and  one  between  the  marginal  plates  and  inner  series, 
upon  each  side  of  the  ray  [probably  the  plates  are  worn  through  by 
weathering;  there  should  be  but  two  rows  of  podial  openings,  the 
others  being  either  muscle  pits  or  weathering  holes].  The  plates  are 
a  little  the  longest  in  the  direction  of  the  length  of  the  ray,  and  in 
this  direction  there  are  about  four  to  the  line.  The  rays  cross  the 
disk  on  the  dorsal  side  and  unite  near  the  center  of  it,  but  the  speci- 
men figured,  Plate  II,  figure  1,  has  this  part  of  the  rays  removed. 
Plate  II,  figure  la,  illustrates  the  ventral  side  of  a  specimen,  which 
is  too  indistinct  to  show  the  arrangement  of  the  plates.  Small 
pieces,  showing  the  ventral  side  of  the  rays,  from  other  specimens, 
have  two  rows  of  spines  springing  from  the  marginal  plates  on  each 
side  of  the  rays." 

Original  description  of  P.  fimbriata.1 — "Disk  of  medium  size,  circu- 
lar. Dorsal  side  of  disk,  and  rays  to  margin  of  disk,  covered  with  a 
granular  integument.  Ventral  surface  of  disk  provided  with  a  large 
number  of  outwardly  directed,  short  and  slender  spines.  Oral 

i  Ulrich  still  maintains  that  this  species  is  a  good  one  and  distinct  from  P.  flexuosus. 


232  BULLETIN  88,  UNITED  STATES  NATIONAL  MUSEUM. 

pieces  10,  subrhomboidal  in  outline,  arranged  in  pairs,  each  pair 
being  formed  of  two  of  the  marginal  series  of  ray  plates ;  on  the  lower 
inner  edge  there  are  five  spines,  and  extending  from  each  pair, 
over  the  mouth,  is  a  bundle  of  rather  long  ones. 

"Rays  apparently  very  flexible,  contracted  toward  the  mouth; 
six  series  of  plates  are  exposed  on  the  ventral  side  of  each  ray.  The 
two  middle  series  [ambulacrals]  alternate  regularly,  and  interlock 
along  the  mesial  line;  they  are  about  twice  as  long  in  the  direction 
of  the  ray,  than  measuring  transversely;  each  piece  is  contracted 
in  the  middle  on  the  inner  side  to  admit  the  wide  ends  of  the  two 
pieces  immediately  opposite,  and  on  the  outer  side  to  form  a  pore- 
like  impression,  between  them  and  the  outer  series  of  plates;  four 
[five  or  possibly  six]  of  these  plates  in  each  range  of  each  ray  are 
included  within  the  disk,  and  the  series  terminate  abruptly  at  a 
distance  of  one  and  a  half  lines  from  the  inner  end  of  the  oral  plates; 
from  the  margin  of  the  disk  to  the  extremity  of  the  ray  there  are 
about  16  pieces  in  each  range.  The  pores  mentioned  above,  are 
occupied  by  a  series  of  loosely  fitting,  obtusely  conical  or  pyramidal 
plates,  some  of  which  distinctly  show  a  deep  depression  in  the  top, 
and  may  have  been  perforated.  Outer  or  marginal  pieces  [side 
plates]  flat,  placed  on  edge,  and  directed  obliquely  outward  so  as 
to  overlap  each  other;  the  two  free  edges,  that  is,  the  one  toward 
the  point  of  the  rays  and  the  one  seen  on  the  ventral  surface,  are 
lined  with  from  10  to  12  short  club-shaped  spines,  varying  somewhat 
in  length.  The  marginal  [side  plates]  and  middle  [ambulacral]  series 
of  plates  articulate  by  means  of  corresponding  prolongations  from 
the  sides  of  the  plates.  These  prolongations  arise  from  near  that 
end  of  the  plate  which  is  directed  toward  the  mouth. 

"  Dorsal  side  of  rays  composed  of  two  rows  of  alternating  and 
interlocking  plates,  which  near  the  disk  are  very  deeply  sculptured 
and  about  as  wide  as  long,  becoming  gradually  less  excavated,  and 
longer  in  proportion  to  the  width,  toward  the  point  of  the  rays;  on 
each  side  they  articulate  with  the  upper  edge  of  the  oblique  mar- 
ginal series  of  plates  [these  are  the  ambulacral  plates  seen  from  the 
dorsal  side,  either  because  there  were  no  dorsal  plates  or  because 
there  was  an  integument]. 

" Breadth  of  disk,  0.60  inch;  breadth  of  arm  at  margin  of  disk, 
0.16  inch;  length  of  same  from  oral  plates,  0.88  inch.  This  species 
is  related  to  Protaster  flexuosus" 

Formation  and  locality. — "This  species  has  been  found  at  differ- 
ent elevations  from  near  low-water  mark  in  the  Ohio  River  [that 
is,  in  basal  Eden]  to  the  top  of  the  hills  at  Cincinnati,"  in  the  upper 
Maysville  beds.  The  type-specimens  of  P.  flexuosus  were  found 
by  Mr.  C.  B.  Dyer  and  are  now  in  the  collection  of  Harvard  Uni- 
versity (Nos.  17,  18).  Those  of  P.  fimbriata  were  obtained  by 


REVISIOH  OF  PALEOZOIC  STELLEEOIDEA.  233 

Ulrich  in  the  lower  Eden  at  about  100  feet  above  low-water  mark 
in  the  Ohio  River  at  Covlngton,  Kentucky.  This  material  is  now 
in  the  Ulrich  collection  of  the  United  States  National  Museum. 
Other  poor  specimens  from  a  still  lower  level  in  the  Eden  and  asso- 
ciated with  Triarihrus  are  from  the  first  ward,  eastern  Cincinnati. 
Two  specimens  are  at  Yale  University. 
Cat.  No.  60615,  U.S.N.M. 

ALEPIDASTER  MIAMIENSIS  (Miller). 

Protaster  miamiensis  MILLER,  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  5,  1882, 
p.  116,  pi.  5,  figs.  6-66.— J.  F.  JAMES,  Journ.  Cincinnati  Soc.  Nat.  Hist., 
vol.  18,  1896,  p.  138.— PARKS,  Trans.  Canadian  Inst.,  vol.  8,  1908,  p.  368. 

Original  description. — "This  species  is  large,  with  a  proportion- 
ally small  disk.  A  specimen  having  a  disk  four-tenths  of  an  inch 
in  diameter,  has  rays  an  inch  in  length.  Five  specimens  have 
been  examined,  all  showing  the  ventral  side.  The  dorsal  side  is 
unknown.  Only  that  part  of  the  disk  between  the  rays  is  visible 
in  any  of  the  specimens,  and  the  plates  are  so  anchylosed  together 
that  no  special  definition  of  them  can  be  given.  The  rays  are  long 
and  coarser  and  stronger  than  usual  in  this  genus,  though  they  were 
quite  as  pliable  and  flexuous  when  living  as  others.  Two  series  of 
subquadrangular  plates,  or  ambulacral  ossicles,  alternating  with 
each  other,  constitute  the  bottom  of  each  ambulacral  furrow;  these 
are  bordered  by  spinous  adambulacral  plates,  which  terminate  at 
the  angles  of  the  mouth  in  only  five  oral  plates." 

Formation  and  locality. — In  the  Richmond  formation,  about 
Waynesville,  Ohio.  The  specimens  are  in  the  Harris  collection 
of  the  United  States  National  Museum. 

Cat.  No.  40886,  U.S.N.M. 

Genus  GREGORIURA  Chapman. 

Gregoriura  CHAPMAN,  Proc.  Royal  Soc.  Victoria,  n.  ser.,  vol.  19,  1907,  p.  24,  pi.  6, 
fig.  1;  pi.  8,  figs.  1,  3. — SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wies- 
baden, vol.  63,  1910,  p.  238. 

Original  definition. — "A  Protasterid  in  which  the  usual  boot- 
shaped  ambulacrals  are  laterally  developed,  and  modified  into  a 
subtriangular  form.  Ossicles  on  each  side  of  the  ambulacral  canal 
subalternate,  excepting  at  the  junction  with  the  mouth  frames, 
where  they  are  parallel.  Adambulacral  ossicles  narrow,  slender, 
extending  laterally  in  a  line  with  the  proximal  border  of  the  ambu- 
lacral ossicle.  Spine-bearing  plates,  slender,  at  right  angles  to  the 
adambulacrals,  carrying  (in  the  genotype)  two  conspicuous  spines. 
Oral  skeleton  having  jaw  plates  three-fourths  the  length  of  the 
mouth  frames;  teeth  thick  and  prominent.  No  traces  of  a  disk 
preserved  in  the  specimen  on  which  the  genus  is  founded.  Arms 
very  slender  and  very  flexible." 


234  BULLETIN  88,   UNITED   STATES   NATIONAL   MUSEUM. 

Genoholotype  and  only  species. — G.  spryi  Chapman  (same  references 
as  above). 

Found  in  the  Siluric  (Melbournian)  shale  at  South  Yarra,  Vic- 
toria, Australia. 

Genus  BUNDENBACHIA  Sturtz. 

Text  fig.  27. 

Bundenbachia  STURTZ,  Palaeontographica,  vol.  32,  1886,  p.  83;  vol.  36,  1890, 
p.  216.— GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1033,  fig.  4 
on  p.  1034.— PARKS,  Trans.  Canadian  Inst.,  vol.  8,  1908,  p.  367.— SCHON- 
DORF,  Palseontographica,  vol.  57,  1910,  p.  57. 

Rays  five,  short,  basally  wide,  terminally  pointed  or  blunt.  Disk 
large,  soft  and  delicate,  with  concave  interradial  margins. 

Abactinally  the  disk  is  covered  with  symmetrical  scales,  and 
medially  there  is  a  pentamerous  rosette  (the  oral  armature  squeezed 
through),  from  the  points  of  which  the  rays  originate.  Rays  covered 

with  a  granular  integument. 

Gregory  states :  "Ambulacral  ossicles  with 
a  dumbbell-shaped  body  and  thin  tapering 
wing.  The  body  of  the  ossicle  is  apparently 
divided  into  two  pieces  by  a  transverse  de- 
pression. The  adambulacral  plates  are  small 
an(*  narrow>  and  support  a  triangular  spine- 
bearing  plate.  [There  is  only  one  plate  here, 

FIG.  27.- VENTRAL  ABM  STRTTC-  L  J  > 

TURK  OF  BUJNDENBACHIA.   EN-    the    adambulacral.     I  here    are    no    lateral 

LARGED.  AFTER  GREGORY.  pieces  as  in  Ophiuroidea.] 

"The  syngnaths  are  curved,  narrow  bars." 
Genoholotype  and  only  species. — B.  beneckei  Sturtz. 
Remarks. — "  Bundenbachia  differs  from  Protaster  by  the  irregular 

nature  and  soft  plating  of  the  disk,  by  the  presence  of  spine-bearing 

plates  attached  to  the  adambulacral  ossicles,  and  by  the  different 

form  of  the  ambulacral  ossicles."     (Gregory.) 

BUNDENBACHIA  BENECKEI  Sturtz. 

Bundenbachia  beneckei  STURTZ,  Palseontographica,  vol.  32, 1886,  p.  83,  pi.  8,  figs.  7, 
7a;  pi.  9,  figs.  1,  la.— GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p. 
1034,  figs.  4. 

Formation  and  locality. — Occurs  in  the  Lower  Devonic  roofing 
slates  of  Bundenbach,  Germany. 

Genus  PAL^EOPHIOMYXA  Sturtz. 

Palseophiomyxa  STURTZ,  Verb,  naturh.  Ver.  preuss.  Kheinl.,  etc.,  vol.  56,  1900, 

p.  202. 
Palxophwmyxidx  STURTZ,  Verh.  naturh.  Ver.  preuss.  Kheinl.,  etc.,  vol.  56,  1900, 

p.  202. — SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63, 

1910,  p.  235. 

Genoholotype  and  only  species. — P.  grandis  (Sturtz). 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  235 

PAL^OPHIOMYXA  GRANDIS  (Sttirtz). 

Bundenbachia  grandis  STURTZ,  Palaeontographica,  vol.  32,  1886,  p.  84,  pi.  9,  figs. 

2,  2a,  3,  3a. 
Palseophiomyxa  grandis  STURTZ,  Verh.  naturh.  Ver.  preuss.  Rhei.nl.,  etc.,  vol.  56, 

1900,  pp.  196,  202. 

Formation  and  locality. — Lower  Devonic  roofing  slates  of  Bun- 
denbach,  Germany. 

Cat.  No.  59388,  U.S.N.M. 

Family  PAL^OPHIURID^E  Gregory. 

Palseophiuridx  GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1034;  Treat. 
Zool.,  vol.  3,  Echinoderma,  1900,  p.  274. — SCHONDORF,  Jahrb.  nassauisch. 
Ver.  Naturk.,  Wiesbaden,  vol.  63,  1910,  p.  237. 

"Lysophiuras  in  which  the  [alternate]  ambulacral  ossicles  consist 
of  a  bar-shaped  or  subquadrate  'body'  without  wings. "  (Gregory, 
1900.) 

Remarks. — This  family  differs  from  the  Protasteridse  in  "having 
the  ambulacral  ossicles  longer  than  wide,  and  never  divided  trans- 
versely by  muscular  depressions.  The  ambulacral  ossicles  are  either 
bar-shaped  or  thickened  to  a  subquadrate  form.  They  are  never 
boot-shaped."  (Gregory,  1897.) 

Schondorf  states  that  Gregory  established  the  families  Protas- 
terida6  and  Palaeophiuridae  on  the  form  of  the  ambulacralia.     He 
says:     "The  first  family  has  boot-shaped,  and  the  second   family 
bar-shaped  or  subquadrate  ambulacrals.     The  form  of  the  latter  is 
nothing  more  than  a  poor  development  of  the  boot-shaped  type  of 
ambulacrals.     Accordingly  the  second  family  has   no  value  and  is 
to  be  withdrawn."     In  addition  the  forms  of  Sturtzura  have  boot- 
shaped  ambulacrals,  and  these  "are  so  little  alternate  in  arrangement 
that   their   alternation   appears    to   me  more   than   questionable." 
(Schondorf,  1910.) 
Contains  the  following  genera: 
Pal&ophiura  Stiirtz. 
Sturtzura  Gregory. 
Eugasterella,  new  name. 
Ptilonaster  Hall. 

Genus  PAL^EOPHIURA  Stlirtz. 

Palxophiura  STURTZ,  Palseontographica,  vol.  36,  1890,  p.  233. — GREGORY,  Proc. 
Zool.  Soc.  London  for  1896,  1897,  p.  1034. 

"  Palaeophiuridse  with  the  disk  surrounded  by  rod-shaped  marginal 
ossicles.  The  ambulacral  ossicles  are  rods  lying  parallel  to  the  arm. " 
(Gregory.) 

Genoholotype  and  only  species. — P.  simplex  Sturtz  (citations  as 
above).  Lower  Devonic,  Bundenbach,  Germany. 


236  BULLETIN  88,   UNITED  STATES   NATIONAL   MUSEUM. 

Genus  STURTZURA  Gregory. 

Sturtzura  GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1034.— SCHON- 
DORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63, 1910,  pp.  215,  237. 

fRhodostoma  SOLLAS  and  SOLLAS,  Philos.  Trans.  Roy.  Soc.  London,  ser.  B,  vol. 
202,  1912,  p.  225  (genoholotype,  Protaster  leptosoma  Salter.) 

"  Palseophiuridse  having  thick,  subquadrate,  ambulacral  ossicles 
and  narrow  adambulacral  plates.  The  disk  is  fragile,  and  its  plates 
are  small  and  thin:  it  has  no  marginal  plates.  The  mouth-frames 
are  narrow  and  separate. 

"Distribution. — Silurian,  England  and  Australia." 

Genoholotype. — Protaster  brisingoides  Gregory. 

"Remarks. — This  genus  differs  from  PalseopTiiura,  as  the  ambu- 
lacral ossicles  are  thick  and  subquadrate,  instead  of  being  in  the 
form  of  narrow  bars;  also  by  the  absence  of  the  strong  marginal 
plates  round  the  disk."  (Gregory.) 

Chapman  in  1907  refers  the  genotype  back  to  Protaster,  adding: 
"In  consequence  of  this  determination  Sturtzura  leptosoma  may  now 
be  considered  as  the  type  of  the  genus."  This  is  in  violation  of  the 
rules  of  nomenclature  and  the  generic  name  will  stand  or  fall  on  the 
basis  of  Protaster  brisingoides. 

Schondorf  states:  "The  ambulacra  of  S.  brisingoides  are  not 
at  all  bar-shaped  or  subquadrate,  if  the  figures  of  Chapman  ( 1907, 
pi.  8,  fig.  2)  are  correct,  but  are  also  essentially  boot-shaped  and 
alternate  in  arrangement.  S.  leptosoma  also  has  alternating  ambu- 
lacra. Their  identity  with  LapwortTiura  miltoni  ranges  them  with 
the  Auluroidea,  where  S.  brisingoides  undoubtedly  also  belongs. 
That  this  form  and  with  it  also  the  genus  Sturtzura  is  to  be  retained 
as  valid  is  very  questionable,  but  the  final  answer  may  as  well  wait 
until  the  originals  are  restudied.  In  any  event  it  is  plain  that 
both  forms  can  not  belong  to  the  Lysophiurse." 

Contains  the  following  species: 
S.  brisingoides  (Gregory).     Siluric  of  Australia. 
S.  leptosoma  (Salter).     Ludlow  of  England. 
S.  leptosomoides  Chapman.     Siluric  of  Australia. 

STtJRTZURA  BRISINGOIDES  (Gregory). 

Tseniaster  australis  McCoY,  see  CHAPMAN  1907,  p.  23  (nomen  nudum). 

Protaster  brisingoides  GREGORY,  Geol.  Mag.,  dec.  3,  vol.  6, 1889,  pp.  24-27,  fig.  1. — 

CHAPMAN,  Proc.   Roy.  Soc.  Victoria,  n.  ser.,  vol.  19,  1907,  p.  22,  pi.  6, 

fig.  2;  pi.  g;  fig.  2. 
Sturtzura  brisingoides  GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1034. 

Formation  and  locality. — From  Siluric  sandstones  at  Moonee  Ponds 
Creek,  Flemington,  near  Melbourne,  Australia.  The  type-material 
is  in  the  British  Museum  (Natural  History),  London.  Other  speci- 
mens from  the  same  locality  and  from  the  parish  of  Yering,  Upper 
Yarra  district.  Victoria,  are  in  the  National  Museum  at  Melbourne. 


REVISION"   OF   PALEOZOIC    STELLEEOIDEA.  237 

STtfRTZURA  LEPTOSOMA  (Salter). 

Protaster  leptosoma  SALTER,  Ann.  Mag.  Nat.  Hist.,  ser.  2,  vol.  20,  1857,  p.  331, 
pi.  9,  fig.  5.— WRIGHT,  Mon.  British  Foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1 
(Palaeontogr.  Soc.  for  1861),  1862,  p.  33.— QUENSTEDT,  Petrefactenktmde 
Deutschlands,  vol.  4,  1876,  p.  133,  pi.  95,  fig.  12.— STURTZ,  Palseonto- 
graphica,  vol.  32,  1886,  p.  79;  N.  Jahrb.  fiirMin.,  etc.,  1886,  vol.  2,  p.  148. 

Sturtzura  leptosoma  GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1035.— 
CHAPMAN,  Proc.  Roy.  Soc.  Victoria,  n.  ser.,  vol.  19, 1907,  p.  26,  pi.  8,  fig.  5 .— 
SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63,  1910, 
p.  215. 

Rhodostoma  leptosoma  SOLLAS  and  SOLLAS,  Philos.  Trans.  Roy.  Soc.  London, 
ser.  B,  vol.  202,  1912,  p.  223,  text  fig.  40,  pi.  9,  figs.  3,  4. 

Formation  and  locality. — Common  in  the  Siluric,  Ludlow  forma- 
tion, at  Leintwardine,  Shropshire,  England. 

Remarks. — Schondorf  says  S.  leptosoma  is  but  a  miniature  edition 
of  Lapworthura  miltoni,  both  forms  being  completely  identical.  The 
disk  margin  is  not  convex  but  concave  between  the  radii. 

STURTZURA  LEPTOSOMOIDES  Chapman. 

Sturtzura  leptosomoides  CHAPMAN,  Proc.  Roy.  Soc.  Victoria,  n.  ser.,  vol.  19, 
1907,  p.  26,  pi.  7,  figs.  1,  2;  pi.  8,  fig.  4. 

Formation  and  locality. — In  the  Siluric  (Melbournian),  Moonee 
Ponds  Creek,  Flemington,  near  Melbourne,  Australia. 

Genus  ETJGASTERELLA,  new  name. 

Eugaster  HALL  (not  Eugaster  Seville  1839,  Orthoptera),  Twentieth  Rep.  N.  Y. 
State  Cab.  Nat.  Hist.,  1868,  p.  290;  rev.  ed.,  1868=1870,  p.  332.— ZITTEL, 
Handb.  Pal.,  vol.  1,  1879,  p.  444.— STURTZ,  N.  Jahrb.  fur.  Min.,  etc.,  1886, 
vol.  2,  p.  151.— MILLER,  N.  Amer.  Geol.  Pal.,  1889,  p.  244.— STURTZ,  Verh. 
naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50,  1893,  p.  20.— GREGORY,  Proc. 
Zool.  Soc.  London  for  1896,  1897,  p.  1035. 

Eugasterella  SCHUCHERT,  Fossilium  Catalogus,  Animalia,  pt.  3,  April,  1914, 
p.  19. 

Original  description. — "Body  stellate,  consisting  of  a  central  alated 
disk,  and  five  long,  slender,  somewhat  flexuous  rays.  Disk  composed 
of  small,  polygonal  tuberculose  or  subspinose  plates  on  the  ventral 
side.  Rays  consisting  of  a  double  series  of  alternating  subquadrate 
ambulacral  ossicles,  and  a  series  of  curved  adambulacral  plates 
bordering  the  grooves,  and  forming  the  margin  of  the  ray;  the  outer 
ends  overlap  the  edge  of  the  next  plate  in  advance.  Oral  plates  ten, 
arranged  in  pairs,  forming  the  terminal  plates  of  the  adambulacral 
ranges.  Pores  large,  arranged  in  two  rows  in  each  ray;  penetrating 
the  ray  at  the  junction  of  the  ambulacral  and  adambulacral  plates 
hi  such  a  manner  that  four  different  plates  border  each  perforation. 
Adambulacral  and  disk-plates  bearing  spines.  Dorsal  surface 
unknown." 

Genoholotype. — E.  logani  (Hall). 


238  BULLETIN  88,   UNITED  STATES   NATIONAL   MUSEUM. 

Gregory  comments  on  this  genus  as  follows : 

"Palseophiuridae  in  which  the  ambulacral  ossicles  are  subhep- 
tagonal  in  form,  the  central  suture  along  the  arm  being  zigzag,  while 
the  outer  angles  of  the  ossicles  are  cut  away  for  the  reception  of  the 
podia.  The  adambulacral  ossicles  have  a  flat  base,  and  thence  bend 
forward  crescentically.  The  mouth  frames  are  massive,  and  those 
of  each  pair  meet  along  the  middle  line  of  the  oral  angle. 

"This  genus  I  only  know  from  Prof.  James  Hall's  figures,  and,  in 
spite  of  their  clearness,  I  feel  much  doubt  as  to  the  wisdom  of  diag- 
nosing it  from  these  alone.  Its  affinities  are  clearly  with  the  Palse- 
ophiuridae,  but  it  approaches  the  Protasteridse  in  one  respect,  for, 
owing  to  the  deep  depressions  in  the  outer  angles  of  the  ambulacral 
ossicles,  the  outer  side  forms  a  short  rudimentary  wing.  The  genus 
differs  from  all  the  Protasteridae  by  the  absence  of  a  muscular  groove 
across  the  ambulacral  ossicles. 

"  Among  the  Palseophiuridse  it  differs  from  Palseophiura  by  the 
absence  of  marginal  ossicles,  and  from  Sturtzura  and  T&niura  by 
the  massive  nature  of  the  mouth  frames." 

Contains : 

E.  logani  (Hall).     Hamilton. 

E.  (?)  concinna  (Ringueberg) .     Rochester. 

EUGASTERELLA  LOGANI  (Hall). 

Eugaster  logani  HALL,  Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  1868,  p.  290; 
rev.  ed.,  1868=1870,  p.  333,  pi.  9,  figs.  7,  8. 

Original  description. — "Body  stellate,  with  a  small  disk  and  long 
attenuate  fiexuose  rays.  Disk  composed  of  numerous  small  poly- 
gonal plates  with  radiated  surfaces;  the  diameter,  measured  from  the 
sinus  to  its  extension  on  the  opposite  ray,  is  about  half  as  great  as  the 
length  of  the  ray  measured  from  the  center  of  the  disk.  Rays,  as  seen 
from  the  ventral  side,  narrow,  attenuate,  with  the  ambulacral  plates 
curving,  and  near  the  base  of  the  rays  a  little  wider  than  long,  and 
toward  the  extremities  longer  than  wide,  with  a  strong  elevated 
transverse  ridge.  There  are  about  eight  pairs  of  plates  inclosed 
within  the  limits  of  the  disk.  Pores  penetrating  the  interstices 
near  the  outer  extremities  of  the  plates,  while  near  the  inner  end  there 
is  a  depression  or  pit  resembling  a  partially  excavated  pore.  The 
adambulacral  plates  as  seen  from  below  are  extremely  narrow  and 
very  convex  on  their  outer  surfaces,  forming  the  margins  of  the  ray. 
Oral  plates  in  pairs,  narrow  and  elongate. 

"This  specimen  measures,  from  the  center  of  the  disk  to  the  extrem- 
ities of  the  rays,  about  one  inch  and  a  half;  the  widest  part  of  the  ray, 
which  is  near  the  margin  of  the  disk,  is  about  an  eighth  of  an  inch 
in  diameter.  The  rays  toward  their  extremities  have  the  ambula- 
cral field  covered  by  the  curving  of  the  marginal  plates  over  the 


REVISION   OF   PALEOZOIC    STELLEROIDEA.  239 

groove,  and  which,  closely  uniting  by  their  margins,  give  a  tereti- 
form  termination  of  nearly  one-third  the  entire  length,  each  one 
having  the  aspect  of  a  slender  crinoidean  proboscis. 

"  Geological  formation  and  locality. — In  the  Hamilton  group,  near 
Fenner,  in  Madison  County,  New  York.  The  specimen  was  collected 
during  the  geological  survey,  and  is  now  in  the  State  Museum." 

EUGASTERELLA  (?)  CONCINNA  (Ringueberg). 

Eugaster  condnnus  RINGUEBERG,  Bull.  Buffalo  Soc.  Nat.  Sci.,  vol.  5,  1886,  p.  8, 
pi.  1,  fig.  3. 

This  species  does  not  belong  to  EugastereUa,  but  until  the  holo- 
type  is  restudied  it  can  remain  in  this  genus.  It  is  from  the  Kochester 
shale  at  Lockport,  New  York,  and  is  in  Dr.  Bingueberg's  collection. 

Original  description. — "Disk  flat,  thin,  alated,  composed  of  very 
fine  granulose  plates.  Rays  broad  at  their  base;  flattened,  rapidly 
tapering  for  two-thirds  of  their  length;  terminal  third  attenuate, 
rounded;  plates,  if  any,  undefinable. 

" Dorsal  side  with  four  series  of  plates;  two  median  and  two  lateral; 
the  transverse  sutures  dividing  the  outer  series  are  continuous  with 
every  other  transverse  suture  dividing  the  central  series.  Medial 
series  with  twice  the  number  of  plates  of  the  outer,  and  are  raised 
above  them. 

"  Sutures  depressed.  Surface  of  the  plates  rounded  and  finely 
granular. 

"The  lateral  series  of  plates  decrease  regularly  in  size  after  reach- 
ing the  disk  until  they  end  in  a  pronounced  elevation  formed  by  the 
last  pair  of  the  medial  series  at  a  point  about  halfway  from  the 
border  toward  the  center  of  the  disk — measuring  at  the  narrowest 
part — where  both  series  end.  Between  these  elevations  the  disk 
has  a  shallow,  stellate  depression  with  the  points  opposite  the  several 
rays.  The  two  outer  rows  of  plates  apparently  disappear  toward 
the  attenuate  tip  before  the  median  does  so.  The  imperfect  cast 
of  the  upper  part  of  one  of  the  rays  is  all  that  is  known  of  the  ventral 
side;  this  shows  traces  of  an  alternating  series  of  ambulacral  plates. 

"Marginal  plates  spiniferous. 

"Length  of  ray,  one-half  inch." 

Genus  PTILONASTER  Hall. 

Ptilonaster  HALL,  Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  1868,  pp.  291-292; 

rev.  ed.,  1868=1870,  p.  334.— LUTKEN,  Dansk.  Vid.  Selsk.  Skrift.,  ser.  5, 

vol.  8,  pt.  3,  1869,  p.   82.— STURTZ,  Palseontographica,  vol.  32,  1886,  p.  83; 

N.  Jahrb.  fur  Min.,  etc.,  1886,  vol.  2,  p.  152.— GREGORY,  Proc.  Zool.  Soc. 

London  for  1896,  1897,  p.  1036. — STURTZ,  Verb,  naturb.  Ver.  preuss.  Rbeinl., 

etc.,  vol.  56,  1900,  p.  188. 
Palseocoma  MILLER  (part),  N.  Amer.  Geol.  Pal.,  1889,  p.  266. 

Original  description. — "Form  and  general  features  as  in  Eugaster, 
but  differing  in  the  plates  of  the  rays.    Rays  composed  of  an  ambu- 

—  Bull.  88 — 15 16 


240  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

lacral,  adambulacral  and  marginal  series,  which  are  united  by  their 
edges,  and  apparently  not  imbricating,  the  projecting  or  oblique 
anterior  face  of  the  marginal  plates  bearing  spines  which  are  inclined 
toward  the  extremity  of  the  ray.  Margins  of  the  rays  alated  by  the 
extension  of  the  disk. 

"I  had  originally  united  this  form  with  Eugaster,  but  further  ex- 
amination has  shown  the  ray  to  have  a  range  of  marginal  plates 
outside  of  the  adambulacral  plates,  and  I  am  unable  to  discover  any 
such  feature  in  Eugaster  logani. 

"This  and  the  preceding  genus  [EugastereTla]  belong  to  the  Ophiu- 
ridae,  to  which  may  also  be  referred  the  genus  Protaster." 

"  Note. — It  is  only  as  these  pages  are  going  to  press  that  my  atten- 
tion has  been  directed  to  the  similarity  of  structure  in  the  ray  of 
Palseocoma  of  Salter  with  that  of  the  proposed  genus  Ptilonaster. 
In  this  illustrated  species  of  the  former  genus  (Palseocoma  marstoni) 
the  disk  is  proportionately  larger,  and  the  rays  much  shorter,  while 
the  outer  range  of  plates  is  represented  as  imbricating;  but  being 
characterized  by  a  double  row  of  plates  bordering  the  ambulacral 
area,  it  must  be  regarded  as  very  nearly  related  if  not  generically 
identical  with  Ptilonaster.11 

Gregory  comments  on  Ptilonaster  as  follows:  "This  genus  is  an  ally 
of  Eugaster;  *  *  *  it  is,  however,  generically  distinct.  I  only 
know  it  from  Hall's  figures,  and  therefore  prefer  to  leave  the  prep- 
aration of  a  formal  diagnosis  to  an  American  palaeontologist." 

GenoJwlotype  and  only  species. — P.  princeps  Hall. 

PTILONASTER  PRINCEPS  Hall. 

Ptilonaster  princeps  HAT.?.,  Twentieth  Hep.  N.  Y.  State  Cab.  Nat.  Hist.,  1868, 

p.  292;  rev.  ed.,  1868=1870,  p.  334,  pi.  9,  fig.  9. 
Palseocoma  princeps  MILLER,  N.  Amer.  Geol.  Pal.,  1889,  p.  267. 

Original  description. — "The  specimen  consists  of  the  impression  of 
the  greater  part  of  one  ray,  with  parts  of  two  others,  and  intervening 
portions  of  the  disk.  The  disk  has  extended  along  the  ray  nearly  an 
inch  from  the  center  of  the  body;  the  plates  are  small,  and  have  been 
furnished  with  slender  spinules.  The  ray  is  strong  and  extremely 
elongate,  having  been  at  least  4£  inches  in  length;  its  greatest  width 
is  outside  of  the  disk,  where  it  measures  seven-sixteenths  of  an  inch. 
The  ventral  side  of  the  ray  shows  three  series  of  plates — ambulacral, 
adambulacral,  and  marginal — on  each  side  of  the  center;  of  these  at 
least  seven  ranges  have  been  included  within  the  disk.  The  ambula- 
cral plates  are  a  little  wider  than  long,  arranged  in  alternating  order. 
The  pores  penetrate  the  interstices  near  the  outer  extremity  of  the 
plates,  while  the  partial  or  obsolete  pores  are  obscure,  becoming 
deeper  and  more  conspicuous  toward  the  extremity  of  the  ray.  Near 
the  base  of  the  ray  there  are  12  plates  in  the  length  of  an  inch, 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  241 

and  14  plates  in  the  same  distance  in  the  central  portion,  while 
toward  the  extremities  there  are  20  or  more  in  the  same  space. 
The  marginal  plates  are  subhexagonal,  a  little  longer  than  wide,  and 
ornamented  by  long  slender  spines  on  their  outer  margins. 

"This  is  a  much  larger  and  more  robust  species  than  the  Eugaster 
logani,  and  in  its  entire  condition  it  is  the  largest  star-fish  known  in 
our  palaeozoic  rocks. 

"  Geological  formation  and  locality. — In  the  Chemung  group.  The 
specimen  is  in  a  brownish-gray  sandstone,  which  weathers  to  a  very 
light  ashen  color.  It  was  received  from  Henry  S.  Randall,  Esq.,  of 
Cortlandville  [New  York],  in  the  vicinity  of  which  place  it  was  ob- 
tained." 

The  holotype,  an  imprint,  is  in  the  American  Museum  of  Natural 
History,  No.  4472. 

Family  ENCRINASTERID^E,  new  name. 

Aspidosomatidse  GREGORY,  Geol.  Mag.,  dec.  4,  vol.  6,  1899,  p.  351;  Treat.  Zool., 
vol.  3,  Echinoderma,  1900,  p.  250.— SCHONDORF,  Palseontographica,  vol.  57, 
1910,  pp.  55-61. 

Palxgoniasteridce  STURTZ  (part),  Palseontographica,  vol.  36, 1890,  p.  246  (contains 
Aspidosomella  and  Palxaster). 

Lysophiurae  with  boot-shaped  ambulacralia  ventrally,  and  large 
disks  that  are  bordered  with  simple  marginalia.  Apparently  only 
the  inframarginals  are  present. 

As  Aspidosoma  Goldfuss  is  preoccupied,  this  name  can  no  longer 
be  used  for  the  family  name.  Encrinaster  Haeckel  replaces  it  and 
therefore  becomes  the  base  of  the  family  designation. 

The  family  has  the  single  genus  Encrinaster. 

Genus  ENCRINASTER  Haeckel. 
Plate  35,  text  fig.  28,  29. 

Aspidosoma  GOLDFUSS  (not  Aspidosoma  Fitzinger  1843,  Keptilia),  Verh.  naturh. 
Ver.  preuss.  Rheinl.,  etc.,  vol.  5,  1848,  pp.  145-146. — SIMONOVITSCH,  Sitzb. 
d.  mat.-naturw.  Classe  Akad.  Wiss.,  Wien.,  vol.  64,  Abt.  1,  1871,  p.  103.— 
ZITTEL,  Handb.  Pal.,  vol.  1,  1879,  p.  451,  fig.  322.— STURTZ,  Palseonto- 
graphica, vol.  32,  1886,  p.  92;  N.  Jahrb.  fiir  Min.,  etc.,  1886,  vol.  2,  p.  151; 
Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50,  1893,  pp.  38,  55.— SCHON- 
DORP, Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  62,  1909,  p.  35; 
Palseontographica,  vol.  57,  1910,  pp.  1-63. — SPENCER,  Mon.  Brit.  Pal.  Aste- 
rozoa,  pt.  1  (Palseontogr.  Soc.  for  1913),  1914,  pp.  23,  24,  49. 

Encrinaster  HAECKEL,  Gen.  Morphologie,  vol.  2,  1866,  p.  Ixvii  (genolectotype 
Aspidosoma  arnoldi  Goldfuss). 

Diagnosis. — Animals  attaining  large  size,  with  a  comparatively 
large  disk.  Rays  five,  more  or  less  petaloid,  slender  and  long,  with 
wide  and  open  ambulacral  furrows. 


242  BULLETIN   88,   UNITED   STATES   NATIONAL    MUSEUM. 

"Ambulacrals  alternating  in  adjoining  columns,  while  the  neigh- 
boring ambulacrals  and  adambulacrals  are  directly  opposite  each 
other.  The  margin  of  the  disk  is  concave  and  limited  by  a  row 
of  more  or  less  conspicuous  simple  [not  two  rows  of  superposed] 
marginalia  restricted  to  the  disk.  The  sides  of  the  free  rays  are 
bounded  by  adambulacrals.  These  and  the  ambulacrals  are  [common 
to  the  two  sides  of  the  animals,  and  abactinally  are]  roughly  sculp- 

tured, usually  naked,  and  only 
in  rare  cases  were  adambulacral 
spines  observed.  Madreporite 
actinal,  situated  near  the  peri- 
stome  in  one  of  the  interradial 
~  I  "c  '  areas  nearest  to  the  left  adam- 

FIG.  28.—  AMBULACKALIA  AND  ADAMBULACRALIA  OF  bulacrals   of  a  radius.7'       (Sch6n- 
ENCRINASTER  ROEMERI,  AFTER  SCHONDORF.    a,  AP-  A^^t    lain  "\ 

-  '  ' 


PEARANCE    OF   THE  PLATES  WHEN  CRUSHED  OR  OB- 
SCTTRED  BY  CLAY.    EACH  AMBULACRAL  HERE  APPEARS 


AS  IF  OF  TWO  PIECES;  b,  SAME  BETTER  PRESERVED        -,-j-  (^Olrlf11^      G.prmq 
OR  MORE  CLEANED;  c,  THE  ACTUAL  FORM  OF  THE  ossi-  noLai  ^°          ss-     ^e 

CLES  WHEN  WELL  PRESERVED  AND  COMPLETELY  to  the  Lower  Devonic  of  Rhenish 


Germany. 

Remarks.  —  This  well-known  genus  has  been  referred  to  the  asterids 
and  to  the  ophiurids,  and  though  it  has  most  often  been  placed 
among  the  true  starfishes,  it  now  appears  to  belong  to  neither  of 
these  orders.  Schondorf  has  restudied  the  material  with  great 
care  and  has  made  out  the  detail  of  the  ambulacralia,  with  the 
result  that  he  erects  for  Aspidosoma  the  order  Auluroidea.  In 
the  work  of  1910  cited  above  the  matter  is  set  forth  in  great  detail, 
and  all  that  can  be  done  here  is  to  direct  atten- 
tion  to  the  more  important  of  his  illustrations, 
with  their  descriptions,  reproduced  in  part  here 
and  on  pages  213  and  214. 

As  Aspidosoma  was  first  used  for  a  genus  of 
reptiles,  it  can  not,  under  the  rules  of  nomen- 
clature, be  used   again  for  another  group  of 
animals.     It   is  possible,  however,  under    the  FIG.  29.—  ORAL  SKELETON  OF 
rules  to  make  use  of  Enerinaster,  but  in  doing    ^7*^™"™! 

SO    the   proceeding  should   first   be    explained.  MUCH    ENLARGED.      AFTER 

Encrinaster  was  proposed  by  Haeckel  as  fol-  SCHONDOEF- 
lows  :  In  defining  his  sixth  order  of  asterids,  the  Crinastra  or  lily  stars, 
forms  that  he  said  already  had  crinoid  characters,  he  cited  as  exam- 
ples of  it  Protaster  sedgwickii  and  P.  =  Aspidosoma  arnoldi.  These 
forms,  he  added,  are  so  different  from  Protaster  miltoni  (  i  that  we  here 
separate  the  former  as  Encrinaster  (E.  sedgwickii,  E.  arnoldi,  etc.)." 
Under  ordinary  circumstances  it  would  be  best  to  disregard  the 
name  because  of  the  inadequate  definition,  but  as  Aspidosoma  is 
preoccupied,  we  are  obliged  to  propose  another  name  to  take  its 


EEVISION   OF   PALEOZOIC   STELLEKOIDEA.  243 

place.  The  first  mentioned  genotype  of  Encrinaster  is  Protaster 
sedgwickii,  but  as  this  is  also  the  type-species  of  Protaster,  a  genus 
in  good  standing,  we  may  accept  the  second  named  species,  Aspido- 
soma  arnoldi.  Therefore  it  is  here  proposed  to  replace  Aspidosoma 
Goldfuss  (not  Fitzinger)  by  Encrinaster  Haeckel,  with  Aspidosoma 
arnoldi  Goldfuss  as  the  genolectotype. 

ENCRINASTER  ARNOLDI  (Goldfuss). 

Aspidosoma  arnoldi  GOLDFUSS,  Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  5, 
1848,  pp.  145-146,  pi.  5.— MULLER,  Verh.  naturh.  Ver.  preuss.  Rheinl., 
etc.,  vol.  12,  1855,  p.  4,  pi.  1,  figs.  1-3.— STURTZ,  Palaeontographica,  vol.  32, 
1886,  p.  93.— SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden, 
vol.  62,  1909,  p.  38;  Palseontographica,  vol.  57,  1910,  pp.  4,  62,  pi.  1,  fig.  2; 
pi.  2,  figs.  6,  7;  pi.  3,  figs.  7-9;  Jahrb.  preuss.  geol.  Landesanst.,  Berlin,  vol. 
29, 1908,  p.  706.— SPENCER,  Mon.  Brit.  Pal.  Asterozoa,  pt.  1  (Palseontogr. 
Soc.  for  1913),  1914,  p.  40. 

Encrinaster  arnoldi  HAECKEL,  Gen.  Morphologie,  vol.  2,  1866,  p.  Ixvii. 

Formation  and  locality. — This  species  is  common  in  the  grauwacke 
of  the  Lower  Coblenzian  at  Winningen,  on  the  Mosel,  Germany. 

ENCRINASTER  GOLDFUSSI  (Schbndori). 

Text  fig.  29. 

Aspidosoma  goldfussi  SCHONDORF,  Palseontographica,  vol.  57,  1910,  pp.  11,  62, 
pi.  3,  figs.  1,  6. 

Formation  and  locality. — A  common  form  found  associated  with 
E.  arnoldi  about  Winningen,  Germany. 

ENCRINASTER  PETALOIDES  (Simonovitsch). 

Plate  35,  figs.  5,  6. 

Aspidosoma  petaloides  SIMONOVITSCH,  Sitzb.  mat.-naturw.  Classe  Akad.  Wiss., 
Wien.,  vol.  64,  Abt.  1,  1871,  p.  106,  pi.  4,  figs.  1-3.— ZITTEL,  Handb.  Pal., 
vol.  1,  1879,  p.  453,  text  fig.  322.— STURTZ,  Palseontographica,  vol.  32,  1886, 
p.  92. — SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  62, 
1909,  p. -37,  pi.  4,  figs.  4,  5;  Palaeontographica,  vol.  57,  1910,  pp.  14,  63,  pi.  1, 
figs.  3,  4;  pi.  2,  fig.  4;  pi.  3,  figs.  10-16  (complete  synonymy  given  here). 

This  species  is  described  in  great  detail  by  its  author  and  by 
Schondorf,  and  is  well  illustrated.  Here  as  elsewhere  the  abactinal 
skeleton  is  that  of  the  actinal  area  seen  from  the  dorsal  side. 

Four  specimens  of  this  species  were  found  in  grauwacke  of  Upper 
Coblenzian  age,  in  the  old  quarry  back  of  the  Hohenrheiner  furnace 
at  Niederlahnstein,  Rhenish  Germany. 

ENCRINASTER  PETALOIDES  GOSLARIENSIS  (Halfar). 

Aspidosoma  petaloides,  var.  goslariensis  HALFAR,  Jahrb.  preuss.  geol.  Lande- 
sanst., Berlin,  vol.  13,  1893,  p.  186,  pi.  10,  figs.  1,  la.— SCHONDORF, 
Palaeontographica,  vol.  57,  1910,  pp.  21,  63,  pi.  2,  fig.  5;  Jahrb.  preuss.  geol. 
Landesanst.,  Berlin,  vol.  29,  1908,  p.  707. 

Formation  and  locality. — The  holotype  is  from  the  Lower  Devonic 
of  the  Harz.  Germany. 


244  BULLETIN  88,   UNITED  STATES   NATIONAL   MUSEUM. 

ENCRINASTER  TISCHBEINIANUS  (Roemer)  emend.  Sttirtz.  » 

Aspidosoma  tischbeinianum  ROEMER,  Palaeontographica,  vol.  9,  1863,  pp.  144-146, 
pi.  23. — QUENSTEDT,  Petrefactenkunde  Deutschlands,  vol.  4,  1876,  p.  76, 
pi.  92,  fig.  39.— STURTZ,  Palaeontographica,  vol.  32,  1886,  p.  92,  pi.  12,  figs. 
1,  2.— SCHONDORF,  Palaeontographica,  vol.  57,  1910,  pp.  23,  62,  pi.  1,  fig.  1; 
pi.  3,  figs.  4,  5  (complete  synonymy  given  here). 

Formation  and  locality. — Common  in  the  roofing  slates  of  the 
Rhenish  Lower  Devonic  at  Bundenbach,  near  Birkenfeld,  Germany. 
As  many  as  60  individuals  have  been  found  on  a  slab. 

Cat.  No.  35117,  U.S.N.M. 

ENCRINASTER  ROEMERI  (SchSndorf). 

Text  fig.  28. 

Aspidosoma  tischbeinianum  ROEMER  (part),  Palaeontographica,  vol.  9,  1863,  pi.  25, 

fig.  11. 

Aspidosoma  roemeri  SCHONDORF,  Palaeontographica,  vol.  57,  1910,  pp.  28,  62, 
pi.  2,  fig.  3;  pi.  3,  figs.  2,  3. 

Formation  and  locality. — Found  associated  with  E.  tiscTibeinianus 
at  Bundenbach,  Germany. 

ENCRINASTER  SCHMIDTI  (SchSndorf). 

Aspidosoma  schmidti  SCHONDORF,  Palaeontographica,  vol.  57,  1910,  pp.  31,  63, 
pi.  1,  fig.  6;  pi.  3,  figs.  17,  18  (complete  synonymy  given  here). 

Formation  and  locality. — A  slab  with  six  specimens  from  the  Lower 
Devonic  (Herdorfer  zone  of  the  Siegen)  at  Oberdielfen;  Germany. 

ENCRINASTER  EIFELENSIS  (SchOndorf). 

Aspidosoma  eifelense  SCHONDORF,  Palaeontographica,  vol.  57,  1910,  pp.  34,  63, 

pi.  1,  fig.  5. 

• 

Formation  and  locality. — Known  by  several  examples  from  the 
Lower  Coblenzian  at  Oberstadtfeld,  Eifel,  Germany. 

ENCRINASTER  PONTIS  (Clarke). 

Aspidosoma  ?  pontis  CLARKE,  Monog.,  I,  Serv.  Geol.  Min.  Brasil,  1913,  p.  312, 
pi.  27,  figs.  1-8;  Bull.  N.  Y.  State  Mus.,  No.  164,  1913,  pi.  35,  figs.  1-4. 

Original  description. — "This  very  graceful  starfish  occurs  in  abund- 
ance in  the  soft  gray  shales  of  Ponta  Grossa,  sometimes  in  clustered 
groups  with  its  long  and  slender  arms  curled  and  intertwined,  more 
often  as  single  individuals  lying  in  beds  with  shells  of  Orbiculoidea 
and  various  lamellibranchs.  I  have  counted  20  individuals  among 
the  specimens  at  my  command  and,  singularly,  every  one  of  these  is 
preserved  with  its  ambulacra!  face  up.  The  removal  of  all  calcareous 
matter  has  left  only  internal  casts  of  this  surface  from  which  it  has 
been  possible  to  gain  an  idea  of  external  structures  from  carefully 


REVISION   OF  PALEOZOIC   STELLEEOI0EA.  245 

made  impressions.  Na  specimen  gives  any  clue  to  the  dorsal  exterior 
save  one  arm  which  has  been  turned  sidewise  showing  a  part  of  that 
surface. 

"The  striking  character  of  this  starfish  is  the  unusual  delicacy  of 
its  arms,  which  are  very  slender  and  long  for  a  true  asteroid  and 
present  an  appearance  very  suggestive  of  an  ophiuran.  These  slender 
arms  are  usually  so  exposed  as  to  show  only  the  alternating  am- 
bulacral  plates  which  increases  the  effect  of  slenderness;  but  the 
adambulacrals  are  occasionally  present  and  give  the  arms  increased 
width.  These  arms  are  all  clearly  sulcate,  the  median  groove  being 
sharply  marked  in  all  casts  by  a  thin  elevated  ridge  running  the 
entire  length  of  the  arm.  The  soft  shale  holding  these  specimens  is 
not  a  very  satisfactory  matrix  from  which  to  take  the  special  struc- 
tures of  the  animal  but  in  good  part  these  can  be  made  out.  The 
ambulacral  plates  are  quadrate  in  outline,  alternate  in  position  along 
the  arm  groove,  and  together  are  arched  so  that  normally  the  am- 
bulacral surface  is  an  arched  ridge  rising  above  the  rest  of  the  surface. 
These  plates,  in  their  arched  position,  are  slightly  spaced  or  dis- 
placed along  adjoining  edges  leaving  passages  from  the  ambulacra. 
They  are  usually  broken  down  or  slipped  over  each  other  in  com- 
pression so  that  the  arm  seldom*  shows  them  in  the  true  position. 
The  surface  of  these  plates  is  finely  granular.  The  adambulacrals 
constitute  one  (or  more  ?)  lateral  rows  and  are  so  seldom  well  defined 
that  I  am  not  able  to  represent  them  with  precision  but  each  of  them 
seems  to  carry  one  short  spine  and  all  to  be  granulated  on  the  surface. 
The  body  of  the  animal  is  deeply  incut  by  the  arms,  which  radiate 
from  a  narrow  center,  sharply  quinquepartite  by  the  buccal  cavity. 
The  oral  apparatus  is  pretty  well  made  out.  The  oral  frames,  one 
for  each  arm,  are  very  conspicuous,  though  varying  in  size  in  different 
individuals.  Each  is  broadly  saddle-shaped,  split  medially,  the  distal 
parts  joined  by  a  suture,  the  proximal  ends  spreading  apart  at  a 
sharp  angle  which  opens  into  the  oral  cavity.  Their  surface  is 
rounded  and  granulate,  the  distal  ends  elevated,  and  often  each  half 
is  inclined  downward  toward  the  other  along  the  median  suture. 
At  each  proximal  angle  lies  a  sharp  jaw  or  tooth.  The  whole  of  the 
body  surface  is  occupied  by  the  oral  rosette  composed  of  the  five 
Jbuccal  divisions." 

Formation  and  locality. — From  the  Devonic  of  Ponta  Grossa  and 
Jaguariahyva,  Brazil. 

ENCRINASTER  (?)  GRAY^E  (Spencer). 

Aspidosoma  grayse.  SPENCER,  Mon.  Brit.  Pal.  Asterozoa,  pt.  1  (Palseontogr.  Soc. 
for  1913),  1914,  pp.  23,  24,  33,  38,  text  figs.  22,  24,  pi.  1,  fig.  8. 

Occurs  in  the  Caradoc  of  Great  Britain. 


246  BULLETIN  88,  UNITED  STATES   NATIONAL   MUSEUM. 

Order  STREPTOPHIUR^   Bell. 

Streptophiurse  BELL,  Proc.  Zool.  Soc.  London  for  1891,  1892,  p.  179.— GREGORY, 

Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1036;  Treat.  Zool.,  vol.  3,  Echino- 

derma,  1900,  p.  274. 
Protophiurex  STURTZ,  Verh.  naturh.  Ver.   preuss.  Rheinl.,   etc.,  vol.  56,  1900, 

p.  200. — SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63, 

1910,  pp.  234,  239,  251. 
Ophiurasterise  SCHONDORF,  Palseontographica,  vol.  57,  1910,  p.  61. 

Diagnosis  by  Gregory  (1897). — Auluroidea  "in  which  the  ambu- 
lacral  ossicles  are  opposite  and  are  generally  fus.ed  into  vertebral 
ossicles.  In  such  cases  the  vertebral  ossicles  articulate  by  a  more 
or  less  simple  ball-and-socket  joint." 

"Remarks. — The  main  character  of  this  order  is  that  the  ambu- 
lacral  ossicles  are  paired,  but  primitive.  The  order  differs  from  the 
preceding  [Lysophiurse]  by  having  the  vertebral  ossicles  always 
opposite  instead  of  alternate.  In  some  of  the  simplest  members  of 
the  order,  as  Ophiurina,  the  ossicles  are  not  fused,  there  are  no 
ventral  arm  shields,  and  an  ambulacral  furrow  runs  along  the  ven- 
tral side  of  the  arm.  In  the  next  higher  family,  as  in  the  genus 
Lapworihura,  the  ambulacral  ossicles  are  fused,  but  have  plain 
articulating  surfaces,  and  there  is*  an  ambulacral  furrow." 
Contains  the  f  amilies : 

Ophiurinidae. 

Lapworthuridas. 

Eoluidiidae. 

Aganasteridae. 

Cholasteridae. 

Family  OPHIUKINIIXE  Gregory. 

Ophiurinidse  GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1037;  Treat. 
Zool.,  vol.  3,  Echinoderma,  1900,  p.  275. — STURTZ,  Verh.  naturh.  Ver.  preuss. 
Bheinl.,  etc.,  vol.  56,  1900,  p.  201.— SCHONDORF,  Jahrb.  nassauisch.  Ver. 
Naturk.,  Wiesbaden,  vol.  63,  1910,  p.  234. 

Original   diagnosis. — "  Strep tophiurae    with    ambulacral    ossicles, 
only  slightly  united,  and  without  ventral  arm  plates." 
Contains  the  genera: 
Ophiurina  Sttirtz. 
Tremataster  Worthen  and  Miller. 

Genus  OPHIURINA  Sturtz. 

Ophiurina  STURTZ,  Palaeontographica,  vol.  36,  1890,  p.  232. — GREGORY,  Proc. 
Zool.  Soc.  London  for  1896,  1897,  p.  1037. 

Gregory's  diagnosis  reads  as  follows:  "Disk  circular,  with  mar- 
ginal plates.  Ambulacral  ossicles  long,  narrow  bars.  Syngnaths 
rod-shaped.  Adambulacral  plates  absent  or  altogether  lost  from 
the  fossil." 


KEVISION   OF  PALEOZOIC   STELLEEOIDEA.  247 

Genoliolotype  and  only  species. — 0.  lymani  Stiirtz  (citations  as 
above).  Lower  Devonic,  Bundenbach,  Germany. 

Genus  TREMATASTER  Worthen  and  Miller. 

Tremataster  WORTHEN  and  MILLER,  Geol.  Surv.  Illinois,  vol.  7,  1883,  p.  330. — 
MILLER,  N.  Amer.  Geol.  Pal.,  1889,  p.  286.— GREGORY,  Proc.  Zool.  Soc. 
London  for  1896,  1897,  p.  1037. 

Original  description. — "Body  stellate,  central  part  discoid,  rays 
long,  flexuous,  and  gradually  tapering.  Rays  consisting  of  a  double 
series  of  ambulacral  plates,  forming,  together,  a  subcuneiform  se- 
ries, with  the  tapering  ends  directed  toward  the  apices  of  the  rays 
and  uniting  with  the  larger  ends  of  the  succeeding  double  plates, 
upon  each  side  of  which  there  is  a  series  of  curved  adambulacral 
plates,  which  form  the  margins  of  the  rays.  The  pores  are  large 
and  situated  between  the  contracting  sides  of  the  ambulacral  plates 
and  the  concave  sides  of  the  curving  adambulacrals.  Four  plates 
border  upon  each  pore  though  nearly  surrounded  by  two  of  them. 
Plates  10.  Dorsal  surface  unknown. 

"This  genus  is  distinguished  by  the  parallel  arrangement  of  the 
ambulacrals  and  adambulacrals,  instead  of  the  alternate  order,  and 
by  the  large  pores." 

Gregory's  diagnosis  is  as  follows:  "Disk  with  concave  inter- 
brachial  outlines.  No  marginal  plates.  Ambulacral  ossicles  short. 
Adambulacrals  present." 

Genoholotype. —  T.  difficilis  Worthen  and  Miller.  T.  (?)  decheni 
(Dewalque)  may  also  belong  here. 

TREMATASTER  DIFFICILIS  Worthen  and  Miller. 

Tremataster  diffidlis  WORTHEN  and  MILLER,  Geol.  Surv.  Illinois,  vol.  7,  1883, 
p.  330,  pi.  31,  figs.  3fl,  36. 

Original  description. — "Body  stellate,  disk  small,  rays  long, 
flexuous,  and  gradually  tapering.  Ambulacral  plates  subtrigonal, 
elongated,  and  united  upon  their  straight  faces  in  parallel  order, 
so  as  to  form  a  series  of  subcuneiform  sections  at  the  bottom  of 
the  ambulacral  groove,  with  the  tapering  end  of  each  directed  toward 
the  apex  of  the  ray,  and  uniting  with  the  larger  end  of  the  next 
succeeding  double  plate. 

"Adambulacral  plates  parallel  with  the  ambulacrals,  and  each 
forms  a  curve  from  the  larger  end  of  an  ambulacral  toward  the 
apex  of  the  ray,  to  unite  with  the  next  succeeding  adambulacral  as 
it  curves  away  from  its  attachment  to  the  ambulacral.  By  this 
order  of  construction  the  adambulacrals  are  fixed,  at  one  end,  to 
the  ambulacrals,  while  the  other  end  moves  upon  the  curved  surface 
of  an  adambulacral  so  as  to  allow  the  same  lateral  flexibility  of 
the  rays,  secured  in  other  genera  by  the  alternate  arrangement  of 


248  BULLETIN   88,   UNITED   STATES   NATIONAL    MUSEUM. 

the  plates.  The  pores  are  large  and  situated  between  the  contract- 
ing sides  of  the  ambulacral  plates,  the  concave  sides  of  the  adam- 
bulacrals,  and  the  attaching  ends  of  the  succeeding  plates,  so  that 
they  are  bounded  by  four  plates  while  nearly  surrounded  by  two. 

"The  oral  plates  form,  in  pairs,  elongated  triangles,  with  the 
acute  angle  directed  toward  the  center  of  the  visceral  cavity.  The 
apices  are  joined  by  a  suture  with  the  basal  portions,  which  are 
partly  separated  by  a  dividing  furrow.  A  single  genital  pore  per- 
forates each  basal  section  of  the  oral  plates.  Dorsal  side  unknown. 

"Locality  and  position:  Prairie  du  Long  Creek,  Monroe  County 
[Illinois],  Chester  limestone. 

"No.  2479,  Illinois  State  collection  of  1878." 

.'  TREMATASTER  (?)  DECHENI  (Dewalque). 

Protaster  decheni  DEWALQUE,  Ann.  Soc.  ge"ol.  Belgique,  vol.  8,  1880,  pp.  52-54, 

pi.  3,  figs.  1,  2. 
Tremataster  (?)  decheni  GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1037, 

footnote. 

Formation  and  locality. — Upper  Devonic  at  Walcourt  (Namur) 
and  Tohogne  (Luxemburg),  Belgium. 

Family  LAPWORTHUKID^E  Gregory. 

Lapworthuridse  GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1037.— 
STURTZ,  Verb,  naturh.  Ver.  preuss.  RheinL,  etc.,  vol.  56,  1900,  p.  203. — 
GREGORY,  Treat.  Zool.,  vol.  3,  Echinoderma,  1900,  p.  275.— SCHONDORF, 
Palseontographica,  vol.  57,  1910,  p.  58;  Jahrb.  nassauisch.  Ver.  Naturk., 
Wiesbaden,  vol.  63,  1910,  pp.  235,  239. 

Furcasteridx  STURTZ,  Verb,  naturh.  Ver.  preuss.  RheinL,  etc.,  vol.  56,  1900,  p. 
203.— SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63, 1910, 
p. 235. 

Palxospondylidsd  STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56,  1900, 
p.  201.— SCHONDORP,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63, 
1910,  p.  235. 

Original  diagnosis. — "Streptophiuroida  without  ventral  armplates 
or  buccal  shields;  ambulacral  ossicles  fused,  but  their  articulating 
surfaces  are  plain.  Madreporite  dorsal."  Schondorf  states  that  this 
plate  is  on  the  ventral  side,  and  that  the  ambulacrals  are  not  fused 
(p.  239). 
Contains  the  genera: 

Squamaster  Ringueberg. 

Lapworihura  Gregory. 

Sturtzaster  Etherrdge. 

Bdellacoma  Salter. 

RTiopalocoma  Salter. 

Hallaster  Stiirtz. 

Sympterura  Bather. 

Fur  caster  Stiirtz. 

Palastropecten  Sttirtz. 


REVISION   OF   PALEOZOIC    STELLEROIDEA.  249 

Sturtz  proposes  that  the  family  Lapworthuridse  be  divided  into 
three  families.  In  the  original  family  will  remain  Squamaster,  Lap- 
worthura,  HaTLaster,  and  Sympterura.  The  family  Furcasteridse  has 
Furcaster,  while  the  Palaeospondylidae  embraces  Palseospondylus,  the 
latter  name  being  later  changed  to  Palastropecten  by  Sturtz,  as  it 
was  preoccupied;  the  family  name  will,  therefore,  have  to  be 
changed  to  Palastropectinidse,  as  was  done  by  Bather  in  1905  (p.  168). 

%  Genus  SQUAMASTER  Ringueberg. 

Squamaster  RINGUEBERG,  Bull.  Buffalo  Soc.  Nat.  Sci.,  vol.  5,  1886,  p.  5. 

Original  description. — "Body  small.  Rays  long,  slender,  tapering, 
flexible,  and  divided  into  annular  segments. 

"Ventral  side  of  ray  with  two  series  of  paired,  opposite  ambulacral 
plates,  divided  by  a  straight  median  line;  they  are  irregularly  sub- 
quadrilateral,  with  one  short  side,  and  are  arranged  in  pairs  in  each 
series,  so  that  two  long  and  two  short  sides  are  joined  alternately; 
consequently  there  is  a  long  transverse  suture  regularly  alternating 
with  a  short  one.  This  disposition  gives  dentate  lateral  margins  to 
the  ambulacral  series.  The  lateral  ends  of  the  long  transverse 
sutures  curve  away  from  each  other,  leaving  a  small  notch  between 
the  inferior  plates  of  each  pair  and  the  superior  plates  of  the  adjoining 
pairs.  This  notch  receives  the  inner  lateral  corners  of  the  squamose 
dorsal  plates.  Between  the  dentate  elevations  of  the  ambulacral 
plates  and  the  lateral  margins  of  the  dorsal  plates  there  are  large 
triangular  openings,  which  constituted,  or  in  which  were  placed,  the 
pores. 

"Dorsal  side  composed  of  large,  quadrangular,  squamose  plates, 
that  encircle  the  arm  as  far  as  the  ambulacral  groove  of  which  they 
form  the  margin.  They  are  divided  in  the  upper  portion  of  the 
ray  by  a  median  suture. 

"Dorsal,  ray  plates  fimbriated  on  the  free  margins. 

"All  plates  are  perforated  by  minute,  closely  arranged  pores." 

Genoholotype  and  only  species. — 8.  echinatus  Ringueberg. 

SQUAMASTER  ECHINATUS  Ringueberg. 

Squamaster  echinatus  RINGUEBERG,  Bull.  Buffalo  Soc.  Nat.  Sci.,  vol.  5,  1886, 
p.  6,  pi.  1,  fig.  1. 

Original  description. — ' '  Body  small.  Rays  long,  slender,  not  widen- 
ing at  the  base ;  regularly  tapering  to  a  subobtuse  point.  Dorsal  side 
covered  by  thin  imbricating  plates,  with  free  external  margins  which 
are  edged  on  the  outer  and  lateral  sides  with  closely  arranged,  long, 
slender,  filiform  spinules,  that  articulate  into  minute  rounded  sockets, 
which  are  scalloped  out  of  the  margin  of  the  plate;  they  are  slightly 
longer  than  the  exposed  portion  of  the  plate,  and  are  placed  about 
their  own  diameter  apart. 


250  BULLETIN  88,  UNITED  STATES   NATIONAL   MUSEUM. 

''Ray  divided  into  about  40  segments  or  articulations  by  the 
encircling,  dorsal  plates;  these  grow  rapidly  narrower  near  the  body, 
and  are  divided  by  a  dorsal  suture  running  along  a  raised  median 
ridge  which  extends  about  two-fifths  of  the  length  of  the  ray  from 
the  body  out,  where  it  gradually  disappears  with  the  last  divided 
plate;  the  rest  are  entire.  These  plates  are  quadrangular,  and  have 
then-  inner  corners  articulated  into  the  socket  formed  in  the  dentate 
lateral  -extensions  of  the  ambulacral  series.  They  are  ornamented 
on  each  side  by  two  or  three  closely  arranged,  subparallel,  very  fine 
ridges,  that  commence  near  the  dorsal  line  at  the  free  margins  and 
extend  diagonally  backward  across  the  plate  toward  the  inner  lateral 
articulated  corner.  Ambulacral  groove  furnished  with  opposite, 
irregularly  quadrilateral,  ambulacral  plates,  divided  by  a  median 
suture  which  is  crossed  alternately  by  one  long  and  one  short  suture. 

"The  superior  plate  of  each  pair  has  the  greatest  extension  later- 
ally, while  in  the  inferior  it  is  the  direction  of  the  median  line,  it 
being  about  twice  as  long  as  the  superior,  which,  however,  is  but 
slightly  broader. 

"Between  the  lateral  margins  of  the  dorsal  plates  and  the  dentate 
elevations  of  the  ambulacral  plates  are  large  sub  trigonal  open  spaces. 

"The  plates  are  punctured  by  very  closely  arranged  minute 
perforations." 

Formation  and  locality. — In  the  Rochester  shale,  at  Lockport,  New 
York.  The  holotype  is  in  the  collection  of  Dr.  Ringueberg.  At 
least  one  (No.  1110)  and  probably  two  other  specimens  (No.  465) 
are  in  the  Walker  collection  of  the  University  of  Toronto.  They  are 
from  the  Rochester  shale,  at  Grimsby,  Ontario. 

Genus  LAPWORTHURA  Gregory. 

Text  fig.  30. 

Lapworthura  GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1037,  fig.  5.— 
SCHONDORF,  Palseontographica,  vol.  57,  1910,  p.  58;  Jahrb.  nassauisch.  Ver. 
Naturk.,  Wiesbaden,  vol.  63,  1910,  p.  208.— SOLLAS  and 
SOLLAS,  Philos.  Trans.  Roy.  Soc.  London,  ser.  B,  vol. 
202,  1912,  p.  213.— SPENCER,  Mon.  Brit.  Pal.  Asterozoa, 
pt>  l  (Pa186011*0^-  Soc.  for  1913),  1914,  pp.  25,  32,  40,  49. 

Original    diagnosis. — "Disk   circular,    well 
marked.     Arms  very  flexible,  broad;  at  first 
FIG.  SO.-VENTRAL  STRUCTURE     uniform  in  width  and  then  tapering  slowly. 
OP  ARM  OF  LAPWORTHURA,     Ambulacral  ossicles  with  the  distal  and  prox- 

AFTER  GREGORY.  .  .  . 

imal  margins  parallel;  with  lateral  wings  curv- 
ing round  the  podial  pores.  Madreporite  large,"  dorsal. 

Genoholotype. — Protaster  miltoni  Salter. 

Schondorf  remarks  as  follows  (1910&:58): 

The  ossicles  of  Lapworthura  have  been  described  several  times, 
but  never  correctly.  The  ambulacrals  are  undoubtedly  opposite, 


REVISION    OF   PALEOZOIC    STELLEROIDEA.  251 

and  both  dorsally  and  ventrally  have  the  structure  of  Encrinaster. 
The  adambulacrals  are  also  opposite  to  the  ambulacrals,  and  have 
long  forward  directed  spines.  In  regard  to  the  dorsal  position  of 
the  madreporite,  he  states  that  the  abactinal  area  has  been  mistaken 
for  the  actinal,  and  that  therefore  the  madreporite  lies  upon  the 
ventral  side. 

The  disk  is  not  circular  in  outline,  but  concave  between  the  inter- 
radii. 

LAPWORTHURA    MILTONI    (Salter). 

Protaster  miltoni  SALTER,  Ann.  Mag.  Nat.  Hist.,  ser.  2,  vol.  20,  1857,  p.  330,  pi.  9, 
fig.  4. — WRIGHT,  Mon.  British  Foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1  (Palse- 
ontogr.  Soc.  for  1861),  1862,  p.  32,  fig.  18.— QUENSTEDT,  Petrefactenkunde 
Deutschlands,  vol.  4, 1876,  p.  75,  pi.  92,  fig.  36.— STURTZ,  N.  Jahrb.  fur  Min., 
etc.,  1886,  vol.  2,  p.  148;  Palseontographica,  vol.  32,  1886,  pp.  79,  94,  pi.  8, 
fig.  6. 

Lapworthura  miltoni  GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1037, 
fig.  5. — SCHONDORF,  Palseontographica,  vol.  57,  1910,  p.  58;  Jahrb.  nassau- 
isch.  Ver.  Naturk.,  Wiesbaden,  vol.  63,  1910,  p.  208.— SOLLAS  and  SOLLAS, 
Philos.  Trans.  Roy.  Soc.  London,  ser.  B,  vol.  202,  1912,  p.  214,  text  figs.  1, 
2,  4  D,  pi.  9,  figs.  1,  2;  pi.  10,  figs.  1-4.— SPENCER,  Mon.  Brit.  Pal.  Aster- 
ozoa,  pt.  1  (Palseontogr.  Soc.  for  1913),  1914,  pp.  25,  32,  35,  36,  pi.  1,  fig.  9. 

Formation  and  locality.- — Abundant  in  the  Lower  Ludlow  of  the 
Siluric  at  Leintwardine,  England.  See  elsewhere  in  this  work 
(p.  237)  under  Sturtzura  leptosoma,  which  Schondorf  states  is  but 
the  young  of  L.  miltoni.  The  same  author  states  further  that  the 
latter  species  either  embraces  several  species  or  the  form  has  a  long 
geologic  range,  for  a  number  of  species  and  genera  appear  to  be 
identical  with  L.  miltoni.  . 

Cat.  No.  59394,  U.S.N.M. 

LAPWORTHURA  SOLLASI  Spencer. 

Lapworthura  sollasi  SPENCER,  Mon.  Brit.  Pal.  Asterozoa,  pt.  1  (Palseontogr.  Soc. 
for  1913),  1914,  pi.  1,  fig.  10. 

Occurs  in  the  Siluric  of  Great  Britain. 

LAPWORTHURA  (?  "probably  n.  gen.")  species  (Miller  and  Gurley). 

Aganaster  (?)  sp.,  MILLER  and  GURLEY,  Sixteenth  Rep.  Geol.  Surv.  Indiana, 
1891,  p.  372,  pi.  9,  figs.  12,  13;  authors'  extracts,  1890,  p.  58.— GREGORY, 
Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1038.  ' 

Original  description. — "We  have  figured  this  fragment  to  show  the 
anchylosis  of  the  oral  plates,  and  the  pores  passing  through  the 
ambulacral  plates,  and  also  those  passing  between  them.  It  will 
be  observed  that  one  pore  passes  through  each  plate  near  the  marginal 
end,  while  a  double  row  of  pores  passes  between  the  plates  in  the 
central  part  of  the  arm  furrow.  We  believe  this  is  an  Aganaster, 
from  the  <Jepth  of  the  central  part  of  the  disk,  and  the  arrangement 
of  the  plates  in  the  arm  furrows;  but  the  specimen  is  larger  than  any 


252  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

Aganaster  gregarius  we  have  seen  and  the  rays  are  wider,  and  as  we 
do  not  know  the  position  of  the  pores  in  the  rays  of  Aganaster,  it 
may  be  our  specimen  does  not  belong  to  this  genus." 

Remarks. — "  Seems  to  me  to  be  allied  to  Lapworfhura,  and  at  least 
a  member  of  the  same  family.  It  apparently  has  no  ventral  arm- 
plates,  but  an  open  furrow,  and  thus  differs  widely  from  Aganaster. 
It  is  probably  a  new  genus."  (Gregory.) 

Formation  and  locality. — Not  given.  The  specimen  may  be  in 
the  Gurley  collection  of  the  University  of  Chicago. 

Genus  STURTZASTER  Etheridge. 

Palaeocoma  SALTER  (not  D'Orbigny  1850),  Rep.  Brit.  Assoc.,  1857,  Trans,  of  sec- 
tions, p.  76;  Ann.  Mag.  Nat.  Hist.,  ser.  2,  vol.  20, 1857,  pp.  324,  327.— WRIGHT, 
Mon.  British  Foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1  (Palseontogr.  Soc.  for  1861), 
1862,  pp.  23,  29. — QUENSTEDT,  Petrefactenkunde  Deutschlands,  vol.  4,  1876, 
p.  81,  pi.  92,  fig.  43.— ZITTEL,  Handb.  Pal.,  vol.  1,  1879,  p.  453.— STURTZ, 
N.  Jahrb.  fur  Min.,  etc.,  1886,  vol.  2,  p.  152;  Verb,  naturh.  Ver.  preuss.  Rbeinl., 
etc.,  vol.  50,  1893,  pp.  45,  62. 

Sturtzaster  ETHERIDGE,  Rec.  Australian  Mus.,  vol.  3,  1899,  p.  129. — SCHONDORF, 
Jabrb.  nassauiscb.  Ver.  Naturk.,  Wiesbaden,  vol.  63,  1910,  p.  217. 

Genoholotype. — Palseocoma  marstoni  Salter. 

Remarks. — Palseocoma  =  Sturtzaster,  Bdellacoma,  and  Rhopalocoma, 
all  of  Salter,  are  ver}^  poorly  known,  due  to  the  fact  that  the  specimens, 
though  not  rare,  occur  in  a  calcareous  shale  and  are  pressed  flat  till 
they  have  become  a  thin  film  of  plates  greatly  obscured  by  an  abun- 
dance of  spines.  Of  P.  marstoni,  the  genotype,  the  writer  has  seen 
five  examples,  presented  to  the  United  States  National  Museum  by 
W.  R.  Billings.  On  the  basis  of  the  characters  revealed  by  these 
specimens,  he  was  inclined  to  leave  the  genus  among  the  Asteroidea 
and  in  close  association  either  with  the  Mesopalaeasterinse  (nearest 
Mesopalseaster,  a  phanerozonian) ,  or  the  Schuchertiidse  (near  Schuch- 
ertia,  a  cryptozonian) . 

The  long,  slender  and  serrated  spines  of  Sturtzaster  are  peculiar  to 
the  genus.  In.  their  abundance  and  character  they  remind  one  more 
of  ophiurids  than  of  asterids. 

The  figures  of  Salter  and  Wright,  if  correct,  recall  the  large-disked 
cryptozonian  genus  Schuchertia,  and  it  was  this  character  that  prob- 
ably also  led  Sttirtz  to  refer  Sturtzaster  to  the  same  group  in  asso- 
ciation with  the  genera  Palasteriscus,  Loriolaster,  and  OTieiropteraster. 

Etheridge  in  1899  called  attention  to  the  fact  that  D ' Orbigny  pro- 
posed in  1850 *  the  new  generic  name  Palseocoma  for  OpJiiura  mulleri 
Phillips  of  the  Lias.  A  name  once  proposed  can  not  be  used  again 
in  another  sense,  and  therefore  Mr.  Etheridge  is  within  the  rules  of 
nomenclature  in  substituting  for  Salter 's  second  usage  of  Palseocoma 

1  Prodome,  vol.  1,  p.  240. 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  253 

the  name  of  Sturtzaster ,  with  Palseocoma  marstoni  SaJter  as  the 
genotype. 

In  1910  Schondorf  was  able  to  study  "several  right  good  examples" 
of  S.  marstoni,  and  strangely  the  form  turns  out  not  to  be  an  asterid 
but  an  aulurid,  with  the  essential  ambulacra!  characters  of  Lap- 
wortJiura  miltoni.  He  states  that  the  ambulacrals  are  not  alternate, 
as  stated  by  Salter,  but  opposite  one  another.  Therefore  the 
ambulacrals  and  the  ad  ambulacrals  are  also  opposite.  The  ad  am- 
bulacrals bear  two  or  three  spines  on  then"  outer  edges,  and  Salter's 
statement  and  figures  showing  two  columns  of  ossicles  outside  of  the 
ambulacrals  appear  to  be  very  wrong.  Schondorf  states  that  the 
peculiar  preservation  of  the  arm  skeleton  has  given  rise  to  this  state- 
ment of  Salter,  and  that  there  are  only  ambulacrals  and  adambula- 
crals  present.  The  oral  skeleton  is  distinctly  adambulacral.  A 
madreporite  is  not  determinable. 

On  the  dorsal  side,  all  that  can  be  clearly  made  out  is  the  presence 
of  ambulacrals  and  adambulacrals,  all  of  which  are  arranged  in  trans- 
verse rows. 

STURTZASTER  MARSTONI  (Salter). 

Palseocoma  marstoni  SALTER,  Ann.  Mag.  Nat.  Hist.,  ser.  2,  vol.  20, 1857,  p.  328, 
pi.  9,  figs.  3a-3c.— WRIGHT,  Mon.  British  Foss.  Echinod.,  Oolitic,  vol.  2, 
pt.  1  (Palseontogr.  Soc.  for  1861),  1862,  p.  30,  fig.  17.— QUENSTEDT,  Petrefacten- 
kunde  Deutschlands,  vol.  4,  1876,  p.  81,  pi.  92,  fig.  43. 

Sturtzaster  marstoni  SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden, 
vol.  63,  1910,  p.  217. 

Formation  and  locality. — Common  in  the  Lower  Ludlow  of  Church 
Hill,  Leintwardine,  England.  Specimens  are  in  many  museums,  the 
United  States  National  Museum  and  the  Yale  Museum  both  having 
individuals.  See  S.  colvini  and  S.  cygnipes. 

Cat.  Nos.  60624,  60625,  U.S.N.M. 

STtfRTZASTER  COLVINI  (Salter). 

Palseocoma  colvini  SALTER,  Ann.  Mag.  Nat.  Hist.,  ser.  2,  vol.  20,  1857,  p.  328. — 
WRIGHT,  Mon.  British  Foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1  (Palseontogr.  Soc. 
for  1861),  1862,  p.  30. 

Sturtzaster  colvini  SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol. 
63,  1910,  p.  219. 

Formation  and  locality. — In  the  Lower  Ludlow,  Leintwardine,  Eng- 
land. "Probably  completely  identical  with  8.  marstoni."  (Schondorf.) 

STtJRTZASTER  CYGNIPES  (Salter). 

Palseocoma  cygnipes  SALTER,  Ann.  Mag.  Nat.  Hist.,  ser.  2,  vol.  20,  1857,  p.  329. — 
WRIGHT,  Mon.  British  Foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1  (Palaeontogr.  Soc. 
for  1861)',  1862,  p.  30. 

Sturtzaster  cygniceps  (QIC)  SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wies- 
baden, vol.  63,  1910,  p.  219. 

Formation  and  locality. — Lower  Ludlow,  Leintwardine,  England. 
"  Probably  completely  identical  with  S.  marstoni."  (Schondorf.) 


254  BULLETIN  88,   UNITED   STATES   NATIONAL   MUSEUM. 

STtJRTZASTER  (?)  MITCHELLI  Etheridge,  jr. 
Sturtzaster  (?)  mitchelli  ETHERIDGE,  jr.,  Rec.  Australian  Mus.,  vol.  3, 1899,  p.  128. 

Formation  and  locality. — A  single  specimen  from  the  Upper  Trilo- 
bite  bed  of  the  Siluric  (Wenlock  series)  at  Bowning,  New  South 

Wales. 

Genus  BDELLACOMA  Salter. 

Palseocoma  (Bdellacoma)  SALTER,  Ann.  Mag.  Nat.  Hist.,  ser.  2,  vol.  20,  1857,  p. 

324.— WRIGHT,  Mon.  British  Foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1  (Palee- 

ontogr.  Soc.  for  1861),  1862,  p.  31.— ZITTEL,  Handb.  Pal.,  vol.  1,  1879,  p. 

453.— STURTZ,  Palseontographica,  vol.  32,  1886,  p.  96. 
Bdellacoma  STURTZ,  Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50, 1893,  pp.  46, 

63. 

Genoholotype  and  only  species. — P.  (B.)  vermiformis  Salter.  Lower 
Ludlow,  Leintwardine,  England. 

Remarks. — Until  this  form  is  restudied  and  brought  up  to  date  the 
supposed  subgenus  of  Paldeocoma  has  no  value. 

Genus  RHOPALOCOMA  Salter. 

Palseocoma  (Rhopalocoma}  SALTER,  Ann.  Mag.  Nat.  Hist.,  ser.  2,  vol.  20,  1857, 
p.  329. — WRIGHT,  Mon.  British  Foss.  Echinod.,  Oolitic,  vol.  2,  pt.  1  (Palae- 
ontogr.  Soc.  for  1861),  1862,  p.  31.— ZITTEL,  Handb.  Pal.,  vol.  1, 1879,  p.  453.— 
STURTZ,  Palaeontographica,  vol.  32,  1886,  p.  96. 

Rhopalocoma  STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50,  1893, 
pp.  46,  63. 

GenoJiolotype  and  only  species. — P.  (R.)  pyrotechnica  Salter.  Lower 
Ludlow,  Leintwardine,  England. 

Remarks. — This  form  also  requires  modernization,  and  until  then 
the  supposed  subgenus  has  no  value. 

Genus  HALLASTER  Sturtz. 

Protaster  HALL  (not  Forbes),  Nat.   Hist.  N.  Y.,  Pal.,  vol.   3,   1861,  p.   134; 

Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  1868,  p.  293;  rev.  ed.,  1868= 

1870,  p.  336. 
Hallaster  STURTZ,  N.  Jahrb.  fur  Min.,  etc.,  1886,  vol.  2,  p.  150. 

Original  description  (Sturtz). — "Ambulacral  plates  alternating 
[they  are  opposite];  the  podial  pores  lie  between  these  and  the  side 
plates.  The  dorsal  skeleton  consists  of  two  columns  of  dorsal  plates 
and  two  of  lateral  plates,  of  which  the  former  adjoin  medially  along 
the  rays.  For  P.  forbesi  Hall  of  the  Silurian  of  North  America  I 
propose  the  generic  name  Hallaster,  because  on  the  one  hand  Forbes 
did  not  sufficiently  characterize  his  Protaster,  and  on  the  other  the 
above  species  in  the  sense  of  Salter's  Protaster  is  not  congeneric 
with  it." 

GenoJiolotype  and  only  species. — Protaster  forbesi  Hall. 

Remarks. — This  genus  appears  to  be  most  closely  related  to  Lap- 
worihura,  with  the  most  obvious  difference  in  the  shape  of  the  am- 


REVISION   OF   PALEOZOIC   STELLEROIDEA. 


255 


bulacral  ossicles.  In  Hallaster  the  lateral  wings  of  the  plates  curve 
round  the  podial  openings  proximally,  while  in  Lapworthura  they  do 
so  distally.  Further,  the  side  plates  of  the  latter  genus  bear  spines 
along  their  sides,  while  in  the  former  genus  they  are  restricted  to  the 
distal  ends  of  the  plates. 

HALLASTER  FORBESI  (Hall). 

Text  fig.  31. 

Protaster  forbesi  HALL,  Nat.  Hist.  N.  Y.,  Pal.,  vol.  3,  1861,  p.  134,  pi.  7 A,  figs. 
8-10;  Twentieth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  1868,  p.  293,  pi.  9,  figs.  5, 
6;  rev.  ed.,  1868=1870,  p.  336,  pi.  9,  figs.  5,  6.— QUENSTEDT,  Petrefacten- 
kunde  Deutschlands,  vol.  4,  1876,  p.  134,  pi.  95,  fig.  13.— STUKTZ,  Palaeonto- 
graphica,  vol.  32, 1886,  pp.  78,  83. 

Hallaster  forbesi  STURTZ,  N.  Jahrb.  fur  Min.,  etc.,  1886,  vol.  2,  p.  150. 

The  original  description  will  not  be  repeated  here  because  it  is 
faulty  and  was  later  corrected  by  Hall. 

Hall's  description  of  1868. — P.  forbesi  "has  a  circu- 
lar disk,  composed  of  squamif  orm  spiniferous  plates 
and  five  long  flexuous  rays.  These  rays  I  have 
[originally]  represented  as  composed,  on  the  lower 
side,  of  a  double  range  of  [adambulacral]  plates,  as 
described  and  represented  by  Professor  Forbes,  but 
finding  outside  of  these  a  range  of  small  ossicles 
[side  plates]  to  which  are  attached  the  spine  bases, 
these  have  been  shown  as  a  part  of  an  articulating 
spine  (in  the  illustration,  plate  7 A1),  an  unnatural  representation, 
which  I  am  now  able  to  correct. 

"In  the  species  from  the  Lower  Helderberg  group,  Protaster  forbesi , 
the  ventral  surfaces  of  the  rays  are  composed  of  an  ambulacral  and 
adambulacral  series  of  plates  on  each  side  [there  are  no  ventral  ray 
plates].  The  ambulacral  plates  are  obliquely  quadrangular  and  alter- 
nating in  a  slight  degree  [in  the  type  they  are  opposite] ;  the  adambu- 
lacral plates  as  seen  from  the  lower  side  are  narrow,  elongate,  oblique, 
and  laterally  imbricating,  presenting  the  appearance  of  an  oblique 
ridge  with  the  anterior  extremity  projecting,  and  forming  the  point 
of  attachment  for  the  spines,  with  which  each  one  is  furnished.  [These 
spines  are  striated  longitudinally.]  When  the  ray  is  abruptly  curved, 
these  plates  project  outward,  sometimes  almost  rectangularly;  and 
when  at  the  same  time  the  ambulacral  area  is  obscured  by  aclhering 
matrix,  these  plates  might  readily  be  mistaken  for  appendages  of 
the  inner  ranges.  The  pores  are  comparatively  large,  truncating 
the  outer  adjacent  angles  of  the  ambulacral  plates,  while  the  base 
of  one  adambulacral  plate  and  the  side  of  another  form  the  exterior 
margin.  The  centers  of  the  upper  sides  of  the  rays  are  composed  of 


FIG.  31.— ACTINAI,  BAT 
PLATES  OP  HALLASTER 
FORBESI  (HALL).  OP- 
POSITE AMBULACRALS, 
AND  THE  SIDE  PLATES. 


*  Nat.  Hist.  New  York,  Pal.,  vol.  3, 1861. 
50601°— Bull.  88—16 17 


256  BULLETIN   88,   UNITED   STATES   NATIONAL    MUSEUM. 

two  ranges  of  subimbricating  [dorsal]  plates,  which  are  closely  joined 
along  the  median  line;  the  marginal  plates  are  the  upper  edges  of  the 
adambulacral  plates,  which  bear  on  their  anterior  ends  one,  two,  or 
three  short  spines." 

Formation  and  locality. — From  the  Coeymans  member  of  the  Hel- 
derbergian  series  of  the  Lower  Devonic,  at  Jerusalem  Hill,  near 
Litchfield,  New  York.  The  holotype  is  in  the  American  Museum  of 
Natural  History,  No.  2302.  There  are  two  good  specimens  and  a 
single  arm  in  the  Beecher  collection  at  Yale  University. 

Genus  SYMPTERURA  Bather. 
Text  fig.  32. 

Sympterura  BATHER,  Geol.  Mag.,  dec.  5,  vol.  2,  1905,  pp.  161-169,  pi.  6,  figs.  1, 
2,  3,  6. — SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63, 
1910,  p.  216. 

Original  diagnosis. — "A  Lapworthurid  with  spinulose  disk  ex- 
tending to  second  arm  segment,  with  oral  skeleton  of  teeth,  long 

A  3 


rame 


t&etk 

FIG.  32.— SYMPTERURA  MINVERI,    AFTER  BATHER.    A.  SEMIDIAGRAMMATIC  RECONSTRUCTION  OF  SYN- 
GNATHS,  X  10.  B.  RECONSTRUCTION  OF  SEVENTH  AND  EIGHTH  ARM  SEGMENTS,  x  18:  a,  DISTAL,  AND  ft, 

PROXIMAL  PORTION  OF  VERTEBRA;  C,  'ADAMBULACRALIAJ  p,  PODIAL   DEPRESSION;  q,  INTERSPACE,  OCCU- 
PIED, AT  LEAST  IN  PART,  BY  INTERVERTEBRAL  MUSCLES. 

jaws,  and  short  mouth  frames  (torus  not  seen),  with  free  arm  seg- 
ments containing  a  vertebral  ossicle,  possibly  compound,  grooved 
ventrally  and  provided  on  each  side  with  two  wings,  to  the  distal  of 
which  is  attached  an  adambulacral  spiniferous  element." 

GenoJiolotype  and  only  species.— S.  minveri  Bather  (same  references 
as  above).  The  holotype  was  found  in  the  Devonic  (?Lower)  at 
Epphaven,  near  Padstow,  North  Cornwall,  England. 

As  this  specimen  presents  in  the  ambulacralia  characters  of  great 
value  in  the  morphology  of  the  Ophiurid  vertebrse,  it  is  advisable 
to  quote  here  somewhat  extensively  from  Bather's  statements. 

"The  median  body  of  each  segment  is  undoubtedly  the  equivalent 
of  the  normal  Ophiurid  vertebra.  On  the  accepted  theory  that 
this -vertebra  was  evolved  by  the  fusion  of  a  pair  of  ossicles  originally 
alternating,  then  opposite,  and  finally  joined  along  the  middle  or 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  257 

radial  line,  the  present  specimen  may  be  described  as  in  a  stage  of 
development  later  than  the  fusion,  but  possibly  retaining  hi  the 
median  groove  a  trace  of  the  primitive  distinctness  of  the  ossicles. 
Those  ossicles  are  usually  described  as  ambulacra!,  and  that  term 
may  be  accepted  so  far  as  it  denotes  homology  with  the  ossicles 
so  named  in  an  Asterid.  *  *  * 

"As  a  rule  among  Ophiurids  in  this  stage  of  evolution,  each  ver- 
tebra has  on  each  side  a  single  side  process  on  which  abuts  an  outer 
ossicle,  the  so-called  adambulacral,  and  these  adambulacrals,  which 
bear  the  lateral  spines,  alternate  with  the  ambulacral  ossicles  or 
vertebrae.  It  is  a  little  difficult  to  interpret  the  appearances  of  the 
present  specimen  in  harmony  with  such  an  arrangement.  On  the 
assumption  that  each  segment  should  contain  one  ambulacral  pair 
(here  fused)  and  one  adambulacral  pair  bearing  spines,  ray  i  has  been 
assigned  nine  segments.  But  each  such  segment  is  seen  to  have  two 
processes  on  each  side,  and  the  distal  one  of  these  bears  the  spines. 
For  this  reason,  and  because  of  the  appearances  in  segment  8,  it  may 
be  supposed  that  the  outer  spiniferous  portion  of  the  distal  process 
(c  in  fig.  1)  is  an  adambulacral  element.  What,  then,  is  the  proxi- 
mal side  process?  To  this  question  two  possible  answers  present 
themselves. 

"The  appearance  of  a  transverse  division  in  the  vertebra,  between 
the  proximal  and  distal  processes,  suggests  that  each  segment  really 
consists  of  two  ambulacral  pairs,  of  which  only  the  distal  one  is 
associated  with  adambulacrals,  the  proximal  pair  of  adambulacrals 
being  suppressed.  Each  of  these  supposed  ambulacral  pairs  pos- 
sesses a  single  pair  of  lateral  processes,  but  those  of  the  distal  pair 
are  partly  overlaid  by  the  adambulacral  elements.  In  the  distal 
region  of  the  ray  the  proximal  and  distal  halves  of  the  vertebra  are 
distinguishable;  but  nearer  the  disk  and  within  it  they  have  come 
closer  together,  the  transverse  division  has  disappeared,  and  the 
side  processes  are  reduced  to  structures  which  appear  as  bars,  but 
are  probably  flattened  laminae.  Thus  the  vertebrae  seen  in  ray  v  are, 
on  this  explanation,  of  compound  origin.  *  *  * 

"Now,  comparison  of  the  vertebrae  of  recent  Ophiurids  with  the  arm 
segments,  especially  the  proximal  ones,  of  our  fossil  leaves  no  room  for 
doubt  that  the  depression  marked  p  is  for  the  reception  of  a  podium, 
while  that  marked  q  is  for  the  insertion  of  the  ventral  intervertebral 
muscles.  A  single  arm  segment  of  a  recent  Ophiurid,  such  as  OpTii- 
amchno,  or  Amphium,  is  therefore  homologous  with  any  one  of  the 
whole  segments  here  numbered  1-8.  If  one  of  these  is  really  com- 
posed of  a  distal  and  a  proximal  hah7  (lettered  a  and  &  respectively 
in  figs.  1  and  2)  the  same  statement  would  apply  to  the  recent  Ophi- 
urid, and  some  trace  of  this  origin  might  be  seen  in  the  development. 


258  BULLETIN   88,   UNITED   STATES   NATIONAL    MUSEUM. 

The  observations  of  Prof.  Ludwig1  and  Mr.  J.  W.  Fewkes2  on 
Amphiura  squamata  have  shown  that  the  two  lateral  halves  of  each 
vertebra  unite  first  at  the  proximal  and  distal  ends,  leaving  a  space 
between.  This  is  suggestive  of  an  origin  from  proximal  and  distal 
elements.  On  the  other  hand  each  lateral  half  springs  from  a 
single  center  of  calcification,  from  which  it  stretches  out  in  a  distal 
direction,  so  that  the  incipient  ambulacral  element  is  thicker  at  its 
proximal  end.  This  last-mentioned  feature  is  paralleled  by  the 
boot-shaped  proximal  portions  of  the  ambulacral  ossicles  in  the  Prot- 
asteridas.  At  a  slightly  later  stage  the  ambulacral  of  Amphiura 
broadens  at  the  distal  end,  which  thus  comes  to  resemble  the  distal 
portion  of  the  Protasterid  ambulacral.  If  this  distal  portion  in 
Amphiura  were,  as  indicated  by  Prof.  Ludwig's  observations,  merely 
an  extension  of  the  proximal  portion,  then  it  might  be  inferred 
that  the  whole  structure,  both  here  and  in  the  various  Paleozoic 
forms  alluded  to,  represented  a  single  ambulacral  pair  and  not  two 
successive  pairs.  In  such  case  one  would  accept  Dr.  Gregory's 
suggested  explanation3  'that  the  smaller  pieces  are  only  triangular, 
distal  portions  of  the  ambulacral  ossicles,  apparently  separated  from 
the  proximal  portion[s]  by  a  groove.'  Dr.  Gregory  further  sug- 
gests that  these  grooves  or  depressions  'were  for  the  lodgment  of 
the  ventral  muscles  which  moved  the  arms.7  A  far  more  probable 
explanation  surely  is  that  they  were  for  the  reception  of  the  branches 
from  the  radial  water- vessel  to  the  podia.  This  explanation,  how- 
ever, consonant  as  it  is  with  the  facts  of  development  of  Amphiura, 
reminds  one  of  another  difficulty.  Prof.  Ludwig4  has  pointed  out 
that,  whereas  the  so-called  ambulacrals  of  Asterids  He  at  right  angles 
to  the  perradius  and  between  the  successive  branches  and  podia, 
those  of  Ophiurids  lie  parallel  to  the  perradius  and  across  the  branches 
to  the  podia.  Now,  if,  as  we  have  every  reason  to  believe,  the  Ophi- 
urids were  derived  from  Asterids,  it  is  hard  to  see  why  this  change 
should  have  taken  place.  That  is  the  difficulty,  but  it  is  a  difficulty 
that  disappears  if  we  suppose  that  the  vertebra  is  really  compounded 
of  two  successive  ambulacral  pairs  in  the  manner  outlined  above. 
The  remaining  objection  to  this  latter '  hypothesis  is  that,  as  Dr. 
Gregory  has  pointed  out,  it  postulates  the  suppression  of  alternate 
podia.  Nevertheless,  similar  fusion  and  concomitant  suppression 
are  not  so  unknown  among  Echinoderms  as  to  render  this  objection 
a  fatal  one. 

"The  suggestion  that  the  vertebrae  of  Ophiurids  are  composed  of 
two  successive  ambulacral  pairs  certainly  can  not  be  proved  with 

1  Zeits.  wiss.  Zool.,  vol.  36, 1881,  p.  181. 

2  Bull.  Mus.  Comp.  ZooL,  vol.  13,  No.  4, 1887. 

»  Proc.  Zool.  Soc.  London  for  1896, 1897,  p.  1032. 
*  Op.  cit.,  p.  185. 


REVISION   OF   PALEOZOIC    STELLEROIDEA.  259 

the  evidence  at  our  disposal.  But  it  is  doubtful  whether  it  can 
be  disproved,  and  I  therefore  make  it  to  promote  a  search  for 
further  evidence  pro  or  con. 

"Two  other  features  in  the  present  specimen  need  discussion, 
and  may  perhaps  throw  light  on  the  problem  just  posed.  The 
first  of  these  is  the  fact  that  the  broadest  and  stoutest  portion  of 
each  arm  segment  appears  to  be  the  distal  half  (marked  a  in  fig.  1), 
whereas  in  the  developing  Ampliiura,  and  in  the  adult  Protasteridse 
the  reverse  is  the  case.  This  character  is  also  found  in  Furcaster 
palseozoicus  as  figured  by  Mr.  Sttirtz,  in  Ptilonaster  princeps  of 
J.  Hall,  and  in  Lapworthura  Miltoni,  as  interpreted  by  Dr.  Gregory. 
(See  our  fig.  4  [30].)  In  the  Epphaven  fossil  the  feature  is  to  some 
extent  accounted  for  by  the  supposed  fusion  of  a  spiniferous  adam- 
bulacral  element  with  the  distal  wing  of  the  ambulacral;  but  in 
Lapworthura  and  Furcaster  this  whig,  while  unconnected  with  the 
adambulacral,  is  still  more  preponderant.  In  some  other  early 
Palaeozoic  genera,  e.  g.  Eugaster,  J.  Hall,  and  EopJdura,  Jaekel, 
the  wing  is  neither  distal  nor  proximal,  but  arises  half  way  up  the 
ambulacral,  so  that  one  can  not  say  to  which  of  two  successive  seg- 
ments the  podium  belongs;  in  fact,  the  structure  is  in  this  respect 
absolutely  that  of  an  Asterid.1  These  differences  call  for  some 
explanation.  Starting  from  the  indifferent  Ordovician  type  of 
EopMura,  we  may  suppose  that  in  one  series  of  genera  (e.  g.  Protas- 
teridse) the  whig  moved  toward  the  mouth,  while  in  another  series 
(e.  g.  Lapworthuridse)  it  moved  away  from  the  mouth.  In  both 
series  the  podium  ultimately  became  inclosed  within  the  substance 
of  (apparently)  a  single  ossicle;  but,  if  this  took  place  by  a  sub- 
sequent lateral  outgrowth  of  stereom,  then  in  the  former  case  the 
vertebra  must  have  inclosed  a  podium  distal  to  itself,  and  in  the 
latter  case  a  podium  proximal  to  itself.  Thus  the  relations  of  the 
vertebras  to  the  podia  would  be  fundamentally  different  in  the 
two  lines  of  descent.  On  the  other  hand,  alternate  podia  may, 
as  suggested  on  a  previous  page,  have  been  inclosed  by  the  union 
of  successive  pairs  of  vertebrae,  and  this  type  of  structure  may 
be  the  one  seen  in  process  of  development  in  the  arm  segments  of 
our  fossil,  and  the  one  that  persisted  to  the  present  day. 

"The  second  feature  worthy  of  attention  is  the  considerable 
space  that  seems  to  intervene  between  the  distal  wing  of  one  seg- 
ment and  the  proximal  wing  of  the  next.  This  is  conspicuous  in  the 
distal  region  of  ray  i,  where,  further,  the  depression  (g  in  fig.  1  [32  B]) 
markedly  resembles  the  podial  depression  (p  in  fig.  1),  and  differs 
from  it  mainly  in  being  rather  nearer  the  axis  of  the  arm.  The 
theory  that  the  Ophiurids  are  descended  from  Asterids  does  not 

i  See  Jaekel,  Zeits.  geol.  Ges.,  vol.  55,  Protok.,  1904,  pp.  106-113. 


260  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

explain  the  evolution  of  such  an  interspace,  and  the  general  tendency 
to  shortening  and  approximation  of  the  vertebrae,  shown  in  the 
history  of  the  Ophiurids,  leads  one  to  inquire  why  there  should 
ever  have  been  introduced  a  stage  in  which,  as  in  the  Devonian 
OpJiiurina,  the  recent  deep-sea  Ophwhelus,  and  the  young  AmpTiiura, 
the  vertebrae  have  so  far  departed  from  the  primitive  type  as  to 
become  axially  elongate.  This  stage  has  been  regarded  as  primi- 
tive by  Lyman,  Ludwig,  and  other  zoologists,  but  in  theory  and 
fact  it  is  ' primitive'  only  so  far  as  the  later  forms  are  concerned, 
while  with  reference  to  the  complete  series  it  is  'intercalated.' 

"Recurring  to  the  hypothesis  that  the  vertebrae  are  compounded 
of  successive  pairs  of  ambulacrals,  we  find  in  it  an  explanation 
not  merely  of  this  curious  elongation  of  the  arm  segments  in  general, 
but  of  the  interspaces  between  them  in  this  genus  (lettered  q).  An 
objection  to  the  hypothesis  was  the  necessity  for  assuming  the  sup- 
pression of  alternate  podia.  Here,  it  may  be,  is  evidence  of  a 
stage  in  which  those  podia  were  not  yet  suppressed,  though  perhaps 
somewhat  atrophied.  If  both  depressions  (p  and  q)  were  for  the 
reception  of  podia,  then  their  alternate  approximation  to  and  re- 
moval from  the  perradius  may  be  compared  with  the  similar  phe- 
nomenon in  Asterids. 

"  Whether  the  features  just  discussed  be  or  be  not  accepted  as 
evidence  in  favor  of  the  compound  origin  of  the  Ophiurid  vertebra, 
they  demand  some  explanation;  and  it  may  be  added  that  the  same 
hypothesis  will  perhaps  furnish  an  equally  needed  explanation  for 
the  hitherto  unexplained  differences  that  obtain  between  Palaeo- 
zoic genera  of  Ophiurids  in  the  relations  of  the  adambulacrals  to  the 
ambulacrals. 

"The  origin  of  the  Ophiurid  mouth-skeleton  also  may  be  illu- 
minated by  the  preceding  hypothesis,  which  is  in  full  harmony  with 
the  opinion  that  many  more  arm  segments  enter  into  the  composition 
of  that  structure  than  is  the  case  in  Asterids,  an  opinion  based  on 
embryological  research  by  Dr.  O.  zur  Strassen,1  and  on  palaeonto- 
logical  investigation  by  Dr.  O.  Jaekel  in  the  paper  quoted  above. 
In  this  region  of  the  ray,  at  any  rate,  adambulacrals  and  podia  must 
have  been  suppressed  in  all  Ophiurids.  We  may  here  note  the 
apparent  absence  from  our  specimen  of  the  adambulacral  elements 
known  as  side  mouth-shields,  as  well  as  of  the  peristomial  plates. 
The  latter  are  wanting  in  most  early  Ophiurids,  a  fact  confirmatory 
of  Dr.  zur  Strassen's  conclusion  that  they  are  not  ambulacral  elements, 
but  '  secondary  calcifications  confined  to  the  interradial  region.' ' 

Schondorf  states  that  the  structure  of  the  arms  is  like  that  in 
LapwortJiura  miltoni  and  the  oral  armature  as  in  Encrinaster. 

i  Zool.  Anzeiger,  vol.  24, 1901,  p.  609. 


REVISION    OF   PALEOZOIC   STELLEROIDEA.  261 

Genus  FURCASTER  Stlirtz. 

Furcaster  STURTZ,  Palaeontographica,  vol.  32,  1886,  p.  79;  N.  Jahrb.  fiir  Min., 
etc.,  1886,  vol.  2,  p.  148;  Verh.  naturh.  Ver.  preuss.  Eheinl.,  etc.,  vol.  50, 
1893,  p.  25.— GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1038; 
Treat.  Zool.,  vol.  3,  Echinoderma,  1900,  p.  275,  fig.  31. 

Disk  small,  circular.  Rays  five,  short,  narrow,  tapering  gradually, 
and  slightly  flexible.  Actinally  flat  and  abactinally  rounded.  There 
is  a  dorsal  median  column  of  slightly  projecting  plates  and  two  lateral 
ranges  of  side  plates.  The  dorsal  plates  are  medially  depressed,  with 
their  outer  sides  extended  into  ears,  into  which  fit  the  spine-bearing 
side  plates. 

"Ambulacral  ossicles  [opposite]  of  a  long  central  body  and  two 
short  wings,  which  are  attached  only  to  the  anterior  corner  of  the 
ossicle."  (Gregory.)  Buccal  scutes  small. 

GenoJiolotype. — F.  palseozoicus  Stlirtz.  F.  (?)  daoulasensis  (Davy) 
may  also  belong  here. 

Remarks. — "In  Stiirtz's  description  he  refers  to  the  existence  in 
this  genus  of  ventral  arm  plates,  and  even  figures  them.  His  type- 
specimens  are  now  in  the  British  Museum,  but  I  can  not  verify  the 
existence  of  any  ventral  arm  plates."  (Gregory.) 

FURCASTER  PALvEOZOICUS  Stiirtz. 

Furcaster  palseozoicus  STURTZ,  Palaeontographica,  vol.  32,  1886,  p.  79,  pi.  8, 
figs.  4,  5;  N.  Jahrb.  fiir  Min.,  etc.,  1886,  vol.  2,  p.  148;  Palaeontographica, 
vol.  36,  1890,  p.  214.— GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897, 
p.  1038. 

Formation  and  locality. — In  the  Lower  Devonic  roofing  slates, 
Bundenbach,  Germany.  There  are  three  specimens  of  this  species 
at  Yale  University. 

Cat.  No.  59383,  U.S.N.M. 

FURCASTER  (?)  DAOULASENSIS  (Davy). 

Protaster  daoulasensis  DAVY,  Bull.  Soc.  geol.  France,  ser.  3,  vol.  14,  1887,  pp.  182- 
187,  text  figs.— GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1038, 
footnote  ("is  an  ally  of  Furcaster"). 

Formation  and  locality. — From  the  Lower  Devonic,  Rumguen,  near 

Brest,  France. 

« 

Genus  PALASTROPECTEN  Sturtz. 

Palastropecten  STURTZ,  Palseontographica,  vol.  32,  1886,  p.  88,  pi.  10,  figs.  3,  4; 
vol.  36,  1890,  p.  213,  pi.  26,  figs.  12,  13.— GREGORY,  Proc.  Zool.  Soc.  London 
for  1896,  1897,  p.  1038. 
Palsespondylus  STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56,  1900, 

p.  190. 
Palxospondylus  STURTZ,  Verh.  naturh.  Ver.  preuss.  Kheinl.,  etc.,  vol.  56,  1900, 

pp.  191,  202. 

Diagnosis  ly  Gregory.— "Disk  circular,  large  (badly  preserved  in 
the  specimens;  probably  originally  soft  and  irregular).  Arms  thick, 


262  BULLETIN   88,   UNITED  STATES   NATIONAL   MUSEUM. 

broad,    and   somewhat   lanceolate   in   shape.     Ambulacral   ossicles 
narrow,  the  lateral  wings  resting  on  the  whole  body  of  the  ossicle.'7 
Genoholotype  and  only  species. — P.  zitteli  (Stiirtz)  (citations  as  above) . 
In  the  Lower  Devonic,  Bundenbach,  Germany. 

Family  EOLUIDIIME  Gregory. 

Eoluidiidx  GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1038. 
Eophiuridss  STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,   etc.,  vol.  56,  1900, 

p.  203. — SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63, 

1910,  p.  235. 

Original  diagnosis. — "  Strep tophiuras  with  the  ambulacra!  ossicles 
united  to  form  vertebral  ossicles.  Ventral  arm  plates  present,  but 
there  are  310  buccal  shields.  (Dorsal  arm  plates  present  only  in 
the  highest  genus.) 

"Remarks. — This  family  includes  three  Devonian  genera,  which 
differ  from  the  previous  families  of  this  order  by  the  presence  of 
ventral  arm  plates  and  by  having  vertebral  ossicles,  which  articulate 
( ?  always)  by  simple  rounded  pits  and  processes.     The  family  differs 
from  living  Streptophiurse  by  the  absence  of  buccal  shields  and 
the  simplicity  of  the  oral  armature." 
Contains  the  genera: 
Eoluidia  Stiirtz. 
Eospondylus  Gregory. 
Miospondylus  Gregory. 

Genus  EOLUIDIA  Sturtz. 

Asterias  asperula  ROEMER  (part),  Palaeontographica,  vol.  9,  1863,  p.  146,  pi.  24, 

figs.  1-5;  pi.  26, -fig.  6;  pi.  27. 
Eoluidia  STURTZ,  Palseontographica,  vol.  32,  1886,  p.  89,  pi.  11,  figs.  1,  2;  vol.  36, 

1890,  p.  211,  pi.  26,  figs.  10,  11.— GREGORY,  Proc.  Zool.  Soc.  London  for 

1896,  1897,  p.  1038.— SOLLAS  and  SOLLAS,  Philos.  Trans.  Roy.  Soc.  London, 

ser.  B,  vol.  202,  1912,  p.  226,  fig.  4E. 
EopMurites  STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56, 1900,  p.  190. 

Diagnosis. — "Disk  rather  large;  the  interbrachial  outlines  are 
deeply  concave.  [Kays  very  long,  slender,  and  fragile.]  Each 
syngnath  consists  of  pairs  of  mouth  frames  and  jaws;  a  jaw  plate 
is  present.  The  vertebral  ossicles  are  small  and  the  union  of  the 
two  lateral  elements  incomplete;  the  lateral  wings  are  thin.  The 
adambulacral  plates  are  triangular  and  each  of  them  bears  several 
spines.  The  pores  for  the  podia  occur  at  the  middle  of  the  lateral 
margin  of  the  ventral  arm  shields. "  (Gregory.) 

Genoholotype  and  only  species. — E.  decheni  Sturtz  (citations  as 
above).  Lower  Devonic,  Bundenbach,  Germany. 

Cat.  No.  35116,  U.S.N.M. 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  263 

Genus  EOSPONDYLUS  Gregory. 

Ophiurella  STURTZ  (not  Agassiz,  1834),  Palseontographica,  vol.  32,  1886,  p.  77. 
Eospondylus  GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1039. 

Original  diagnosis. — "Disk  circular.  Ambulacral  ossicles  com- 
pletely fused  into  vertebral  ossicles,  each  of  which,  however,  is  trav- 
ersed by  a  pore.  The  adambulacral  ossicles  are  somewhat  pear- 
shaped.  The  podial  pores  are  at  the  posterior  angles  of  the  ventral 
arm  plates." 

Genoholotype  and  only  species. — Ophiurella  primigenia  Stiirtz. 

EOSPONDYLUS  PRIMIGENIUS  (Stiirtz). 

Ophiurella  primigenia  STURTZ,  Palseontographica,  vol.  32,  1886,  p.  77,  pi.  8, 

figs.  1,  2;  vol.  36,  1890,  p.  210,  pi.  26,  figs.  6,  7. 
Eospondylus  pnmigenia  GREGORY,   Proc.   Zool.   Soc.   London  for  1896,   1897, 

p.  1039. 

Formation  and  locality. — Lower  Devonic,  Bundenbach,  Germany. 

Genus  MIOSPONDYLUS  Gregory. 

Ophiura  rJienana  STURTZ,  Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  50,  1893, 

p.  29,  pi.  1,  figs.  1-3. 
Miospondylus  rhenanus  GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p. 

1039. — SOLLAS  and  SOLLAS,  Philos.  Trans.  Koy.  Soc.  London,  ser.  B,  vol. 

202,  1912,  p.  226. 

Onginal  diagnosis  (Gregory). — "Disk  circular.  Ambulacral  ossi- 
cles completely  united;  each  half  of  the  vertebral  ossicle  is  boot- 
shaped.  The  oral  angles  each  consist  of  a  pair  of  syngnaths  without 
jaw  plate.  The  ventral  arm  plates  are  small  and  are  not  notched 
by  podial  pores." 

Genoholotype  and  only  species. — Opliiura  rhenana  Stiirtz  (citations 
as  above).  Lower  Devonic,  Bundenbach,  Germany. 

Remarks. — Eospondylus  and  Miospondylus  "  agree  in  family  char- 
acters with  Eoluidia,  but  differ  from  it  in  the  structure  of  both  the 
ambulacral  and  adambulacral  plates."  (Gregory.) 

Family  AGANASTERID.^  Stiirtz. 

Aganasteridse  STURTZ,  Verb,  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56,  1900, 
p.  203. — SCHONDORP,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63, 
1910,  p.  235. 

Genus  AGANASTER  Miller  and  Gurley. 

Aganaster  MILLER  and  GURLEY,  Sixteenth  Rep.  Geol.  Surv.  Indiana,  1891,  p. 
372;  authors'  extracts,  1890,  p.  57.— GREGORY,  Proc.  Zool.  Soc.  London  for 
1896,  1897,  p.  1039. 

^  Ophiopege  BOHM,  Zeit.  geol.  Gesell.,  vol.  45,  1893,  p.  159  (same  genoholotype  as 
for  Aganaster). 

Original  description. — "In  1869  Meek  and  Worthen  described  an 
Ophiuroidea,  in  the  Proceedings  of  the  Academy  of  Science  of 


264  BULLETIN  88,  UNITED   STATES   NATIONAL   MUSEUM. 

Philadelphia,  page  169,  under  the  name  of  Protaster  gregarius,  which 
they  redefined  and  illustrated  in  the  Geological  Survey  of  Illinois, 
volume  5,  page  509,  under  the  name  of  Protaster  ( ?)  gregarius.  They 
had  numerous  specimens  'in  the  condition  of  casts  and  molds,  in 
a  very  fine,  somewhat  granular  matrix,  that  did  not  show  the  details 
of  its  structure  very  clearly/  but  they  said,  'It  will  probably  be 
found  to  be  generically  distinct  from  the  Silurian  typical  forms  of 
Protaster,  but  we  prefer  to  place  it  provisionally  in  that  genus  for  the 
present.'  In  the  collection  of  Mr.  Gurley  there  are  several  specimens 
belonging  to  this  species,  and  they  show  a  few  characters  not  ob- 
served by  Meek  and  Worthen,  and  demonstrate  very  clearly  this 
species  does  not  belong  to  the  genus  Protaster;  we  therefore  propose 
to  include  this  species  in  a  new  genus,  Aganaster,  and  describe  the 
characters,  so  far  as  known,  as  follows: 

"  General  outline,  a  central  circular  disk  with  five  long,  narrow 
rays ;  the  circular  disk  on  the  dorsal  side  is  covered  with  small  polygo- 
nal plates  which  are  not  interrupted  by  the  presence  of  the  rays, 
thus  showing  the  disk  had  a  depth  greater  than  the  depth  of  the 
rays;  rays  very  narrow  and  convex  or  half  cylindrical,  spine  bearing, 
gradually  tapering,  and  from  the  dorsal  side  appear  as  if  composed 
of  plates  arranged  exactly  opposite  each  other;  the  ventral  side  shows 
a  rather  deep  central  disk  with  marginal  plates.  There  are  10  oral 
plates  in  the  central  part  of  the  disk." 

Genoholotype  and  only  species. — Protaster  gregarius  Meek  and 
Worthen. 

Remarks. — Aganaster  "has  nothing  to  do  with  Protaster  and  is 
clearly  a  member  of  the  Streptophiurse.  As  far  as  its  characters  are 
known  to  me  it  must  be  included  among  the  Eoluidiidae.  It  differs 
from  the  rest  of  this  family  by  the  presence  of  dorsal  arm  plates. 
*  *  *  Bohm  has  founded  the  genus  OpJiiopege  on  the  type  species 
of  Aganaster."  (Gregory.) 

AGANASTER  GREGARIUS  (Meek  and  Worthen). 

Protaster  f  gregarius  MEEK  and  WORTHEN,  Proc.  Acad.  Nat.  Sci.  Philadelphia, 
vol.  21,  1869,  p.  169;  Geol.  Surv.  Illinois,  vol.  5,  1873,  p.  509,  pi.  16,  fig.  5. 

Alepidaster  gregarius  MEEK,  Amer.  Journ.  Sci.,  ser.  3,  vol.  4,  1872,  p.  275  (gen. 
ref.  only). 

Aganaster  gregarius  MILLER  and  GURLEY,  Sixteenth  Rep.  Geol.  Surv.  Indiana, 
1891,  p.  372,  pi.  9,  figs.  10,  11;  authors'  extracts,  1890,  p.  57,  pi.  9,  figs.  10, 
11.— MILLER,  N.  Amer.  Geol.  Pal.,  1st.  App.,  1892,  p.  673,  fig.  1208. 

Description  of  1873. — "The  disk  of  this  species  is  circular  in  out- 
line, slightly  convex  above,  and  measures  from  0.20  to  0.30  inch  in 
diameter.  In  most  cases  it  looks  as  if  merely  covered  by  a  smooth, 
membranaceous  integument.  Some  casts  of  its  external  surface, 
however,  seem  to  show  traces  of  flat,  nearly  smooth,  imbricating 
scales  above.  The  five  arms  are  slender,  flexible,  and  rather  long 


KEVISION   OF   PALEOZOIC   STELLEROIDEA.  265 

in  proportion  to  breadth.  In  a  specimen  with  a  disk  measuring 
0.25  inch  in  breadth,  the  diameter  of  the  arms  near  the  disk  is  only 
0.05  inch.  None  of  the  specimens  show  the  entire  length  of  the  arms, 
though  some  fragments  of  them  were  seen  lying  detached  in  the 
matrix,  about  0.55  inch  in  length,  without  being  complete  at  either 
end.  From  the  breadth  and  gradual  taper  of  these,  it  would  seem 
probable  that  when  entire  they  may  have  been  0.75  to  1  inch  in  length. 
Their  impressions  in  the  matrix  give  no  indications  of  a  longitudinal 
furrow  along  the  under  side,  but  show  that  there  were  about  six 
pairs  of  arm  pieces  in  a  length  of  0.16  inch.  These  pieces  appear 
to  be  nearly  though  not  exactly  opposite,  and  each  one  provided 
below  with  a  comparatively  large,  round,  deep  pit,  or  pore,  near 
the  middle  of  its  anterior  side.  Along  their  lateral  margins  there 
appear  to  be  impressions  in  the  matrix  of  very  small  spines  (one  to 
each  arm  piece),  though  if  such,  they  must  have  been  extremely 
short.  Impressions  of  the  upper  side  of  the  slender  arms  show 
them  to  have  been  somewhat  rounded  above,  with  the  nearly  square 
arm  pieces  slightly  alternating.  Some  of  the  impressions  seem  to 
show  traces  of  central  pores  or  pits,  one  at  the  middle  of  each  pair 
of  pieces,  though  in  others  no  traces  of  these  are  visible/7 

Formation  and  locality. — Common  as  molds  in  a  fine  impure 
sandstone  and  in  the  famous  crinid  bed  at  Crawfordsville,  Indiana, 
in  the  Keokuk  formation  of  the  Mississippic. 

There  are  two  specimens  (No.  6)  of  this  species  in  the  Wachsmuth 
collection  at  Harvard  University.  At  Yale  University  there  are 
four  specimens. 

Family  CHOLASTERID^  Worthen  and  Miller. 

Cholasteridse  WORTHEN  and  MILLER,  Geol.  Surv.  Illinois,  vol.  7,  1883,  p.  328. 
Original  deHnition. — Cholaster  "is  so  widely  different  from  those 
heretofore  discovered  that  we  think  it  belongs  to  a  distinct  family, 
which  might  very   appropriately  be  designated  the  Cholasteridse, 
but  until  other  specimens  have  been  found  showing  other   parts 
of  the  body,  we  prefer  to  let  the  family  remain  undefined." 
Contains  the  genus : 

Cholaster  Worthen  and  Miller. 

Genus  CHOLASTER  Worthen  and  Miller. 

Cholaster  WORTHEN  and  MILLER,  Geol.  Surv.  Illinois,  vol.  7,  1883,  p.  328.— 
GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1040. 

Original  description.— Dorsal  side  alone  known.  "Body  trun- 
cated pentagonal,  central  area  circular,  deep  and  large  in  propor- 
tion to  the  rays;  rays  distant,  smaU,  short  and  abruptly  truncated. 


266  BULLETIN  88,   UNITED   STATES   NATIONAL   MUSEUM. 

" Dorsal  side  possessing  a  rather  large  centro-dorsal  plate,  which 
is  surrounded  by  five  plates  occupying  the  position  of  radials,  while 
the  other  part  is  covered  with  numerous  small  disk  plates. " 

Gfenoholotype  and  only  species.- — C.  peculiaris  Worthen  and  Miller. 

Gregory  states  that  CJiolaster  "appears  to  be  allied  to  Aganaster, 
but  the  structure  of  the  ambulacral  ossicles  is  unknown." 

CHOLASTER  PECULIARIS  Worthen  and  Miller. 

Cholaster  peculiaris  WORTHEN  and  MILLER,  Geol.  Surv.  Illinois,  vol.  7,  1883, 
p.  329,  pi.  31,  figs.  4a,  4b. 

Original  description. — "The  general  form  of  the  body  is  that  of  a 
truncated  pentagonal  star,  with  a  large  circular  disk.  A  centro- 
dorsal  plate  is  surrounded  by  five  others,  all  of  which  are  much  larger 
than  other  plates  of  the  body,  and  occupy  a  centro-dorsal  depres- 
sion. The  position  of  these  five  plates  is  that  of  radials,  resting 
upon  a  basal,  and  therefore  all  other  plates  of  the  body  might  be 
regarded  as  radials  and  interradials,  the  latter  being  very  numer- 
ous, because  of  the  wide  separation  of  the  rays  at  their  junction 
with  the  body.  The  interradials  are  polygonal,  convex,  or  sub- 
spinous  plates,  without  much  variation  in  size  whether  filling  the 
larger  or  smaller  interradial  spaces.  The  plates  following  the  larger 
radial  plates,  as  above  defined,  in  the  direction  of  the  rays,  are  not, 
however,  by  their  form  or  arrangement  to  be  distinguished  from 
the  interradials,  though  differing  from  those  forming  the  rays. 
The  plates  covering  the  dorsal  side  are  thus  divided  into  three 
kinds,  viz.:  First,  the  larger  plates  filling  the  centro-dorsal  depres- 
sion; second,  the  disk  plates  which  cover  all  other  parts  of  the  body 
except  the  rays,  and,  third,  the  plates  which  cover  the  rays  proper, 
which  in  this  species  are  easily  distinguished  from  the  central  disk 
plates. 

"The  rays  are  short,  abruptly  truncated,  and  slightly  expanded 
at  the  apices  by  reason  of  an  enlargement  of  the  terminal  plates. 
They  are  widely  separated  from  each  other,  though  not  at  uniform 
distances,  and  present  the  appearance  of  having  been  stuck  on  the 
central  disk,  instead  of  having  grown  from  it,  an  appearance  more 
marked,  by  reason  of  the  change  in  the  form  of  the  plates,  from  the 
disk  to  the  rays. 

"One  of  the  interradial  spaces  is  much  greater  than  the  others, 
so  that  a  line  may  be  drawn  across  the  disk,  leaving  three  entire 
rays  upon  the  smaller  half.  The  back  of  each  ray  is  covered  by  a 
series  of  transversely  elongated  plates  separated  from  the  side 
series  by  a  longitudinally  impressed  line.  A  single  series  of  plates 
covers  either  side  of  a  ray,  interlocking  with  the  transverse  dorsal 
series  and  directed  backward  toward  the  disk. 

"The  oral  plates  are  unknown,  and  no  madreporiform  tubercle 
has  been  detected." 


REVISION   OF   PALEOZOIC   STELLEBOIDEA, 


267 


Formation  and  locality. — Okaw  Bluffs,  between  Chester  and 
Kaskaskia,  Illinois,  in  the  Chester  formation  of  the  Upper  Missis- 
sippic.  The  holotype  is  in  the  Illinois  State  collection,  No.  2480. 

Subclass  OPHIUROIDEA. 

These  animals  are  not  present  in  the  older  Paleozoic,  may  have 
appeared  in  the  late  Devonic,  and  <Jo  not  seem  to  have  been  abundant 


FIG.  33. — OPHIOTERESIS.  AFTER  BELL  FROM  GREGORY. 
ABORAL  SURFACE  OF  AN  ARM  OSSICLE:  a,  ARTICULAR 
CAVITIES;  d,  THE  DOUBLE  DORSAL  SHIELDS;  I,  LATERAL 

ARM  PLATES. 


FIG.  34.— SYNGNATHS  OF  OPHIURA  CIUARIS. 
AFTER  MULLER  FROM  GREGORY.  ;,  JAW; 
m.f.,  MOUTHFRAME;  n,  g.,  GROOVE  FOR  CIR- 

CUMCESOPHAGEAL  NERVE-RING;  p. d.,  PORE 
AND  DEPRESSION  FOR  ORAL  TENTACLE. 


before  the  Triassic,  since  which  time  they  occur  more  and  more  com- 
monly. In  the  present  oceanic  waters  they  are  popularly  known  as 
sand-stars,  brittle-stars,  branching-stars,  or  basket  starfish.  They 
range  from  shallow  and  estuarine  waters  to  abyssal  depths.  Typical 
Ophiuroidea  differ  from  typical  Asteroidea  in  having  the  arms  sharply 
marked  off  from  the  disk  as  appendages,  and  in  the  absence  of 
grooves  along  the  actinal  side  of  the  arms.  This  means  that  the  body 
cavity  which  in  the  Asteroidea  extends  out  into  the  rays  is  restricted 
in  the  Ophiuroidea  to  the  disk. 

The  subclass  Ophiuroidea  is  defined  by  Schondorf  as  follows: 
"Ainbulacral  water-vascular  system  situated  in  a  small  groove 
at  the  base  of  the  ray  ossicles,  and  ventrally  covered  by  a  single 
column  of  ventral  shields.  From  the  radial  canal  outside  of  the 
ambulacrals  arise  simple  lateral  branches  that  never  have  ampullae, 
as  a  rule  curve  upward,  pass  into  and  through  the  substance  of  the 
ossicles,  and  finally  open  out  laterally  between  the  ventral  and  side 
shields  as  the  ambulacral  podia.  Ambulacrals  opposite,  each  right 
and  left  piece  coossified  into  a  vertebra  with  complicated  articular 
surfaces  [see  figs.  34-36].  Adambulacrals  transformed  into  lateral 
shields.  Vertebrae  dorsally  covered  by  a  single  column  of  dorsal 
shields."  Disk  circular  in  outline,  lt without  marginal  plates,  and 
sharply  separated  from  the  rays,  that  as  a  rule  are  rounded.  There 
is  no  typical  madreporic  plate.  One  of  the  ventrally  situated  mouth 
shields  serves  as  madreporite"  (1910a:  246). 


268  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

In  ophiurids  the  oral  skeleton,  or  syngnaths,  is  composed  of  three 
pairs  of  adambulacrals  and  ambulacrals.  Of  these  the  two  first 
pairs  alone  are  prominent  and  preserved.  The  third  pair  remains 
internal,  small,  and  rudimentary. 

Family  ONYCHASTERID^  Miller. 

Onychasteridae  MILLER,  N.  Amer.  Geol.  Pal.,  1889,  p.  216.— GREGORY,  Proc.  Zool. 
Soc.  London  for  1896,  1897,  p.  1040. — STURTZ,  Verh.  iiaturh.  Ver.  preuss. 
Kheinl.,  etc.,  vol.  56,  1900,  p.  202.— SCHONDORF,  Jahrb.  nassauisch.  Ver. 
Naturk.,  Wiesbaden,  vol.  63,  1910,  p.  235. 

Original  diagnosis. — "  Strep tophiurse  with  well-developed  vertebral 
ossicles,  and  with  very  flexible,  contorted,  unbranched  arms;  there 


U.S.  "• 

u.  ^ 


FIGS.  35  AND  36. — VERTEBRAL  OSSICLE  OF  OPHIURA  CILIARIS.     AFTER  MULLER  FROM  GREGORY.    35; 
ABORAL  SURFACE;  36,  ADORAL  SURFACE,    c,  CANAL  FOR  THE  PODION  (SHOWN  BY  REMOVAL  OF  A  PART  OF 

MUSCLE  FIELD  ON  RIGHT  SIDE);  J.W.,  LOWER  MUSCLE  FIELD;  l.f.,  LOWER  AND  «./.,  UPPER  CANAL  FURROWS, 
«.,  UMBO;  U.  *.,  UMBONAL  SOCKET. 

are  no  external  arm  plates,   the  integument   containing  granules 
only.'7 

Contains  the  genus : 

Ony chaster  Meek  and  Worthen. 

Genus  ONYCHASTER  Meek  and  Worthen. 

Onychaster  MEEK  and  WORTHEN,  Geol.  Surv.  Illinois,  vol.  3,  1868,  p.  526;  Proc. 
Acad.  Nat.  Sci.  Philadelphia,  vol.  21, 1869,  p.  82;  Geol.  Surv.  Illinois,  vol.  5, 
1873,  p.  474.— ZITTEL,  Handb.  Pal.,  vol.  1,  1879,  p.  443.— MILLER,  N.  Amer. 
Geol.  Pal.,  1889,  p.  264.— STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc., 
vol.  50,  1893,  p.  30.— GREGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p. 
1040.— STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56, 1900,  p.  183. 
—SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  62,  1909, 
pp.  47-61,  vol.  63,  1910,  p.  240;  Palaeontographica,  vol.  57,  1910,  p.  59.— 
SPENCER,  Mon.  Brit.  Pal.  Asterozoa,  pt.  1  (Palseontogr.  Soc.  for  1913),  1914, 
pp.  26,  50.— I.  B.  J.  SOLLAS,  Philos.  Trans.  Hoy.  Soc.  London,  ser.  B,  vol. 
204, 1913,  p.  51.— SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden, 
vol.  66,  1913,  pp.  97-114. 


REVISION   OF   PALEOZOIC   STELLEEOIDEA. 


269 


Genoholotype. — 0.  flexilis  Meek  and  Worthen. 

For  generic  description,  see  under  0.  flexilis. 

Remarks  ly  Gregory.- —"This  interesting  genus  has  hitherto  been 
placed  among  the  Euryalidse,  of  which  it  has  been  regarded  as  the  best 
known  fossil  representative.  As  Prof.  Bell,  however,  has  remarked, 
Meek  and  Worthen's  clear  figures  of  the  vertebral  ossicles  show  that 
the  articular  surfaces  are  Strep tospondy line  and  not  Cladophiuroid." 

Schondorf  in  1909  restudied  Ony chaster  hi  detail,  and  came  to  the 
following  conclusions : 

u  Ony  chaster  flexilis  shows  plainly  in  the  structure  of  its  arm  ossicles 
that  it  belongs  to  the  Ophiuroidea.  As  in  this  subclass,  so  also  in 
Onychaster  the  arm  ossicles  originated  from  two  halves  (ambulacrals) 
that  grew  tightly  together.  When  compared  with  living  Ophiurids,  this 


40 


41 


FIGS.  37-41  .—ONYCHASTER  FLEXILIS.    AFTER  SCHONDORF.  37  AND  38,  PROXIMAL  VERTEBRA  SEEN  FROM 

THE  ABORAL  AND  ADORAL  SURFACES.  39,  VENTRAL  VIEW  OF  TWO  PROXIMAL  VERTEBRA,  ORIENTED 
WITH  THE  ABORAL  SIDE  UP  AND  THE  ADORAL  DOWN.  40,  SIDE  VIEW  OF  SAME.  ADORAL  SIDE  ON  LEFT, 
ABORAL  ON  RIGHT.  41,  VENTRAL  VIEW  OF  SEVERAL  SUCCESSIVE  VERTEBRA  WITH  THE  ABORAL  SIDE 
AT  THE  TOP.  O,  UPPER  LATERAL  ARTICULAR  KNOB;  O',  SOCKET  FOR  KNOB  OF  ADORAL  SIDE;  C,  INSERTION 
FIELD  FOR  THE  UPPER,  AND  0,  FOR  THE  LOWER  INTERMEDIARY  VERTEBRAL  MUSCLES;  gr,  MEDIAN  UN- 
PAIRED DEPRESSION;  gr\,  SMALL  DEPRESSION  FOR  THE  KNOB,  fci,  OF  THE  ADORAL  SIDE;  gr«,  LARGE  DE- 
PRESSION OF  THE  CENTRAL  AREA  OF  VERTEBRA;  TO,  BARRIER  SEPARATING  THE  UPPER  AND  LOWER 
INTERMEDIARY  VERTEBRAL  MUSCLES;  T,  LATERAL  GROOVE  (?  FOR  LATERAL  BRANCHES  OF  WATER- 
VASCULAR  SYSTEM);  S,  VENTRAL  PROJECTION  OF  THE  LATERAL  KNOBS  OF  ADORAL  SIDE;  t  AND  t' ,  UNPAIRED 
MEDIAN  ARTICULAR  KNOB  AND  SOCKET. 

amalgamation  of  the  two  arm  ossicles  in  Onychaster  is  still  plainly  to  be 
seen.  The  equivalent  skeleton  of  the  adambulacrals  in  the  asterids  is 
not  yet  completely  separated  from  the  arm  ossicles  nor  developed  into 
independent  side  or  lateral  shields ;  on  the  contrary,  they  still  remain 
attached  and  in  articulation  with  the  arm  ossicles  on  their  ventral  outer 
margin.  On  their  somewhat  fluted  outer  margin  they  bear  a  few  spines. 
The  arm  ossicles  are  not  externally  naked  but  are  covered  by  smaller 
additional  plates  that  bear  flat  calcareous  particles.  Individual  large 
dorsal  shields  do  not  appear  to  be  present,  for  on  the  large  Berlin  speci- 
men the  arm  ossicles  lie  directly  beneath  the  small  flat  dorsal  plates. 
Only  in  the  distal  part  of  the  rays  does  one  observe  some  rows  of 


270  BULLETIN  88,   UNITED  STATES  NATIONAL   MUSEUM. 

apparently  independent  dorsal  plates,  that  overlie  one  another  in 
a  scalelike  manner,  but  this  determination  needs  to  be  substantiated 
on  better  preserved  material.  Along  the  median  line  of  the  arm 
ossicles  there  lies  ventrally  a  single  column  of  ventral  plates,  that 
bear  spines  and  externally  cover  the  radial  canal  of  the  water  vas- 
cular system.  The  lateral  branches  from  the  radial  canal  to  the 
ambulacral  podia  do  not  penetrate  the  substance  of  the  arm  ossicles 
as  in  living  ophiurids,  but  lie  between  each  pair  of  vertebrae.  The 
oral  skeleton  consists  of  five  interradially  placed  mouth-corner 
pieces.  Each  one  of  these  is  made  up  of  three  elements,  the  two 
outer  of  which  are  united  into  pairs"  (pp.  60-61). 
Contains  the  following  species : 

0.  flexilis  Meek  and  Worthen.     Keokuk. 

0.  asper  Miller.     Keokuk. 

0.  barrisi  (Hall).     Burlington. 

0.  confragosus  Miller.     Keokuk. 

0.  demissus  Miller.     Keokuk. 

ONYCHASTER  FLEXTLIS  Meek  and  Worthen. 
Text  figs.  37  to  42. 

Onychastei*  flexilis  MEEK  and  WORTHEN,  Geol.  Surv.  Illinois,  vol.  3,  1868,  p.  526, 
figs.  A-D;  Proc.  Acad.  Nat.  Sci.  Philadelphia,  vol.  21, 1869,  p.  83;  Geol.  Surv. 
Illinois,  vol.  5,  1873,  p.  510,  pi.  16,  figs.  3a-3Z.— ZITTEL,  Handb.  Pal.,  vol.  1, 
1879,  p.  444,  fig.  314.— MILLER,  N.  Amer.  Geol.  Pal.,  1889,  p.  264,  fig.  374.— 
SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  62,  1909, 
pp.  47-61;  vol.  63,  1910,  p.  240.— I.  B.  J.  SOLLAS,  Philos.  Trans.  Roy.  Soc. 
London,  ser.  B,  vol.  204,  1913,  pp.  51-62,  text  figs.  1-4,  pi.  8,  figs.  1-6.— 
SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  66,  1913,  pp. 
97-114,  text  figs.  1,  2,  pi.  3,  figs.  3-9.— SPENCER,  Mon.  Brit.  Pal.  Asterozoa, 
pt.  1  (Palseontogr.  Soc.  for  1913),  1914,  pp.  26,  50. 

Original  description. — "The  interesting  fossil  on  which  we  propose 
to  found  this  genus  and  species  seems  to  differ  so  widely,  in  some  of 
its  characters,  from  the  true  starfishes,  as  well  as  from  the  Ophi- 
urians,  as  to  leave  doubts  whether  it  can  be  properly  placed  in  either 
of  these  groups  as  now  understood.  *  *  *  In  habit  and  general 
appearance  it  most  nearly  resembles  the  Ophiurians,  from  which, 
however,  it  differs  widely  in  structure.  It  is  composed  of  a  rather 
small  subdiscoid  body,  and  five  long,  slender,  rounded,  flexible  arms 
or  rays.  In  nearly  all  of  the  specimens  yet  found  the  arms  are  folded 
together  like  the  claws  of  a  bird  when  grasping  some  small  object. 
A  few  of  them,  however,  have  the  arms  opened  out  more  or  less,  so 
as  to  show  that  they  were  very  flexible,  or  capable  of  being  moved 
about  in  all  directions.  They  usually  increase  slightly  in  thickness 
for  a  short  distance  from  the  body,  then  taper  very  gradually  to  their 
extremities,  being  about  2.50  inches  in  length,  and  0.22  inch  in 
breadth,  at  the  widest  part. 


KE VISION   OF  PALEOZOIC   STELLEKOIDEA.  271 

"On  the  dorsal  side  of  the  body  *  *  *  there  is  seen  a  compar- 
atively large  circular  area  or  disk,  composed  of  an  outer  circle  of  ten 
rather  prominent  pieces,  united  together  in  five  pairs  by  close-fitting 
sutures,  each  piece  being  pierced  by  a  round  ovarian  ?  pore.  Imme- 
diately within  this  circle  there  is,  apparently,  another  circle  of  ten 
smaller  pieces,  also  united  in  five  pairs,  but  without  pores;  and  within 
this  latter  circle  there  is  a  third  range  of  five  still  smaller,  nonporif- 
erous  pieces,  surrounding  a  central  anal?  opening;  the  whole  re- 
minding one  of  the  apical  disk  of  an  Echinoid,  though  differing  in 
structure  from  this  part  of  the  known  types  of  that  group.  It  is 
also  worthy  of  note  that  there  is  some  analogy  between  this  disk  and 
the  body  of  a  crinoid,  excepting  that  there  is  a  central  opening,  and 
thnt  the  first  division  of  the  radial  series  takes  place  immediately  on 
the  inner  range  of  pieces  corresponding  to  the  basal  pieces  of  a  crinoid, 
while  all  of  the  third  range  of  pieces  are  pierced  by  pores.  *  *  * 

"Immediately  outside  of  the  circle  of  ten  pore  pieces,  mentioned 
above,  each  pair  of  these  pieces  is  succeeded  by  two  or  three  pairs  of 
differently  formed,  interlocking,  transverse  pieces,  in  direct  range,  con- 
necting them  with  the  dorsal  side  of  each  of  the  five  rays.  A  little  far- 
ther out  the  dorsal  side  of  the  rays,  these  transverse  pieces  are  seen 
to  become  disconnected  by  more  or  less  wide  spaces,  and  gradually 
pass  into  pairs  of  lanceolate  pieces,  deeply  furrowed  longitudinally, 
while  between  the  inner  ends  of  the  two  pieces  of  each  pair  there 
appears  to  be  a  porelike  opening.  These  latter  disconnected  pieces 
continue  all  the  way  out  to  the  extremities  of  the  rays,  and,  with 
numerous  smaller  intervening  ossicles,  form  together,  as  it  were,  the 
skeleton  or  framework  of  the  long  flexible  rays.  It  is  only,  however, 
when  an  outer  granular  integument  has  been  removed  that  this 
skeleton  structure  can  be  seen.  In  some  parts  of  some  of  our  specimens 
this  outer  granular  covering  remains,  and  is  seen  to  be  composed  of 
numerous  small,  rounded,  rather  prominent  ossicles,  regularly 
arranged  in  qui[n]cunx,  so  as  to  give  the  surface  a  chagreenlike  rough- 
ness. These  ossicles  were  doubtless  attached  to,  and  secreted  by,  a 
soft  dermal  envelope,  covering  the  whole  surface,  while  the  larger 
pieces  within  formed  the  frame,  as  it  were,  of  the  whole  structure, 
and  probably  furnished  points  of  attachment  for  the  muscles  that 
moved  the  rays. 

"None  of  our  specimens  show  clearly  the  inner  side  or  ambulacral 
furrows  of  the  rays,  nor  the  under  side  of  the  body — consequently 
we  know  nothing  of  the  nature  or  position  of  the  mouth  or  of  the 
ambulacra.  In  several  instances,  however,  we  have  seen  the  remains 
of  one  or  more  rows  of  small,  short,  longitudinally  striated  spines 
along  the  inner  side  of  the  arms. 

50601°— Bull.  88—15 18 


272  BULLETIN  88,   UNITED   STATES   NATIONAL   MUSEUM. 

"The  entire  breadth  of  a  mature  individual,  across  between  the 
extremities  of  the  rays  on  opposite  sides,  if  these  rays  were  straight- 
ened out,  would  be  about  5  to  6  inches." 

Formation  and  locality. — This  species  occurs  quite  commonly  in 
the  famous  crinid  bed  at  Crawfordsville,  Indiana,  in  the  Keokuk 
formation  of  the  Mississippic.  Specimens  are  in  several  American 
museums;  two  are  at  Yale  University,  others  in  the  United  States 
National  Museum. 

Cat.  No.  59392,  U.S.N.M. 

ONYCHASTER  ASPER  Miller. 

Onychaster  asper  MILLER,.  Seventeenth  Rep.  Geol.  Surv.  Indiana,  1892,  p.  684, 
pi.  12,  figs.  3-5;  advance  extras,  1891,  p.  74,  pi.  12,  figs.  3-5.— MILLER,  N. 
Amer.  Geol.  Pal.,  App.  1,  1892,  p.  680,  fig.  1240;  App.  2,  1897,  p.  749,  fig*. 
1366.— KEYES,  Missouri  Geol.  Surv.,  vol.  4,  1894,  p.  131. 

Original  description. — "  Dorsal  side  covered  with  an  integument  of 
small  plates  and  numerous  short  spines.  Central  disk  rather  large, 
circular,  convex,  inflated  from  the  point  of  contact  with  the  arms. 
The  outer  integument  covers  the  whole  surface  of  the  central  disk, 
leaving  no  orifice  exposed.  Where  the  outer  integument  is  worn  off 
the  disk  is  composed  of  rather  large,  polygonal  spine  bearing  plates. 
The  spines  do  not  arise  from  the  center  of  the  plates,  but  laterally 
from  little  pits  or  sockets  at  the  sutures.  These  sockets  give  the 
plates  a  somewhat  sculptured  appearance.  The  spines  have  a  bulb 
at  the  base  and  taper  to  an  obtuse  point  above. 

"The  arms  are  long,  rounded  on  the  dorsal  side,  and  very  flexible. 
Figure  4  shows  the  arms  abruptly  folded  from  the  middle  over  the 
ventral  part,  while  figures  3  and  5  have  the  arms  folded  like  the  claws 
of  a  bird  grasping  some  small  object.  There  is  a  row  of  spines  on  each 
side  of  the  arm  furrows. 

"This  species  is  so  different  from  the  type  that  the  generic  reference 
is  very  doubtful." 

Formation  and  locality. — In  the  Keokuk  formation  of  the  Missis- 
sippic, at  Boonville,  Missouri.  The  specimens  are  said  to  be  in  the 
Miller  and  F.  A.  Sampson  collections. 

ONYCHASTER  BARRISI  (Hall). 

Protester  f  barrisi  HALL,  Desc.  N.  Sp.  Crinoidea,  1861,  p.  18. 
Onychaster  ?  barrisi  MEEK  and  WORTHEN,  Proc.  Acad.  Nat.  Sci.  Philadelphia, 
vol.  21, 1869,  p.  83;  Geol.  Surv.  Illinois,  vol.  5,  1873,  p.  476,  pi.  10,  figs.  la-Id 

Hall's  original  description. — "  A  fragment  of  an  Asterias}  among  the 
Burlington  fossils,  presents,  in  the  rays  and  in  the  oral  plates,  some 
characters  in  common  with  Protaster;  but  I  can  discover  no  evidence 
of  a  central  disk.  The  fragment  preserves  the  center  of  the  lower 
side  and  parts  of  four  rays.  All  that  remain  of  the  rays  are  two 
distinct  ranges  of  plates,  which,  near  the  base,  are  separated  by  a 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  273 

wide  groove,  but  farther  on  appear  to  come  in  contact  on  their  inner 
margins.  These  plates  consist  of  joints  closely  articulated  together, 
with  a  longitudinal  foramen:  their  lower  sides  are  marked  lengthwise 
by  a  comparatively  wide  but  not  deep  groove.  The  body  of  the  plate 
has,  on  each  side,  a  lateral  arching  process  which  is  jointed  at  the 
two  extremities,  and  separated  in  the  center  by  a  pore-like  perfo- 
ration. There  are  ten  oral  plates,  two  from  each  division  of  the  ray: 
these  plates  are  expanded  vertically;  their  extreme  points  have  the 
inner  edges  slightly  curving;  the  lower  external  faces  are  slightly 
indented,  or  crenulate ;  the  surface  of  attachment  is  wide  and  strong, 
and  constricted  at  the  base  by  a  distinct  groove,  beyond  which  it 
again  expands. 

"This  form,  if  really  without  a  disk,  differs  essentially  from  Prot- 
aster;  and  there  are  also  other  differences,  which  may  make  it 
necessary  to  constitute  a  distinct  genus  when  better  specimens  shall 
be  obtained." 

Formation  and  locality. — In  the  Burlington  limestone  at  Burlington, 
Iowa.  There  are  three  specimens  of  this  species  in  the  Wachsmuth 
collection  (Nos.  10,  11,  and  12)  at  Harvard  University. 

ONYCHASTER  CONFRAGOSUS  Miller. 

Onychaster  confragosus  MILLER,  Seventeenth  Rep.  Geol.  Surv.  Indiana,  1892, 
p.  684,  pi.  12,  figs.  6,  7;  advance  extras,  1891,  p.  74,  pi.  12,  figs.  6,  7. 

Original  description. — "This  species  is  so  different  from  the  one  ^ast 
described  [0.  asper],  and  also  from  the  type  of  this  genus,  that  it  may 
not  be  congeneric  with  either  of  them.  I  have  no  doubt  that  it 
belongs  to  the  same  family.  I  have  seen  only  the  dorsal  side  of  the 
disk  and  the  dorsal  and  lateral  sides  of  the  rays.  There  is  no  such 
integument  of  small  plates  covering  the  dorsal  side  as  belongs  to 
0.  asper,  but  the  surface  is  covered  with  short  spines. 

"The  central  part  of  the  disk  is  somewhat  injured  in  our  specimens, 
and  its  character  can  not  be  definitely  determined.  It  is  surrounded 
by  large,  centrally  convex,  six-rayed  plates.  These  rays  seem  to  be 
the  elevated  ridges  that  separate  the  sockets  for  the  insertion  of  the 
spines.  Outside  of  this  circle  of  ten  six-rayed  plates,  there  is  a  circle 
of  quadrilateral  plates  more  or  less  sculptured  by  the  sockets  for  the 
spines,  and  here  the  radials  may  be  said  to  commence.  The  dorsal 
side  of  each  ray  consists  of  three  series  of  plates,  and  there  is  one 
series  upon  each  side,  or  five  series  in  an  arm.  The  first  plates  are 
connected  laterally  by  smaller  ones,  in  the  angular  depressions, 
between  the  commencement  of  the  rays,  which  form  part  of  the  disk* 
All  of  the  radial  plates  are  more  or  less  sculptured  by  the  depressions 
for  the  insertion  of  the  spines.  The  spines  are  longer  than  the  diam- 
eter of  a  plate,  bulbous  at  the  lower  end,  and  taper  to  an  obtuse  point. 
The  arms  are  long,  round  on  the  dorsal  side,  flexible  and  capable  of 
being  rolled  up  on  the  ventral  side  or  being  twisted  laterally.  No 


274  BULLETIN   88,    UNITED   STATES    NATIONAL    MUSEUM. 

such  ovarian  pores  piercing  the  plates  of  the  disk,  as  described  and 
illustrated  in  O.flexilis,  have  been  discovered." 

Formation  and  locality. — In  the  Keokuk  formation,  at  Boonville, 
Missouri.  The  cotypes  are  said  to  be  in  the  Miller  collection. 

ONYCHASTER  DEMISSUS  Miller. 

Ony chaster  demissus  MILLER,  Seventeenth  Rep.  Geol.  Surv.  Indiana,  1892,  p.  685, 
pi.  12,  figs.  8-10;  advance  extras,  1891,  p.  75,  pi.  12,  figs.  8-10;  N.  Amer. 
Geol.  Pal.,  App.  1,  1892,  p.  680,  fig.  1241. 

Original  description. — "This  species  hangs  its  arms  down  and  folds 
them  like  the  claws  of  a  bird  grasping  some  small  object,  and  in  these 
respects  is  more  like  0.  flexilis  than  either  of  the  preceding  species. 
The  central  disk  is  slightly  concave,  subpentagonal  in  outline,  and 
the  rays  drop  down  at  right  angles  to  the  circumference  of  the  disk. 

"In  the  center  of  the  disk  there  is  a  low,  subcircular  elevation,  in 
which  I  have  been  unable  to  find  any  sutures,  or  to  determine  whether 
or  not  there  is  an  opening  of  any  kind ;  it  appears  to  consist  of  a  single 
plate.  It  is  surrounded  by  a  series  of  ten  plates  that  form  the  sub- 
pentagonal  rim  of  the  central  disk.  These  plates  are  large,  very 
convex,  radiately  sculptured,  and  bent  down  in  the  direction  of  the 
radial  series  as  well  as  curving  in  to  unite  with  the  central  plate.  The 
sculpturing  is  due  to  the  sockets  for  the  insertion  of  the  rays.  The 
radial  series  commence  from  this  circle  of  plates.  The  rays  are 
angular  on  the  dorsal  side  or  obtusely  rounded.  The  dorsal  side  of 
each  ray  consists  of  three  series  of  plates,  and  there  is  one  series  on 
each  side,  or  five  series  in  an  arm.  The  first  two  plates  in  each  ray 
are  connected  laterally  by  smaller  ones,  which  form  part  of  the  disk, 
in  the  angular  depressions,  between  the  commencement  of  the  rays. 
All  of  the  radial  plates  are  more  or  less  sculptured  or  pitted  by  the 
depressions  for  the  insertion  of  the  spines. 

"The  arms  are  longer,  more  angular,  and  have  rather  smaller  spines 
than  either  of  the  preceding  species.  I  have  been  unable  to  detect 
any  ovarian  pores,  but  spine  sockets  very  much  resembling  pores  are 
indicated  in  figure  8,  but  they  occur  in  the  sutures  and  are  readily 
distinguished  from  pores  that  pierce  the  plates." 

Formation  and  locality. — In  the  Keokuk  formation,  at  Boonville, 
Missouri.  The  three  cotypes  are  said  to  be  in  the  Miller  collection. 
There  are  two  good  specimens  (No.  10994)  in  the  Gurley  collection  at 
the  University  of  Chicago,  and  another  specimen,  from  Crawfords- 
ville,  Indiana,  in  Yale  University. 

FORMS  WHOSE   RELATIONSHIPS   ARE  UNKNOWN. 

CRIBELLITES  CARBONARIUS  Tate. 

Cribellites  carbonarius  TATE,  Rept.  Brit.  Assoc.  Adv.  Sci.,  for  1863,  1864,  Notices 
and  abstracts,  p.  88. 

Original  description. — "This  Asteroid,  the  first  recorded  from  the 
Mountain  Limestone,  is  an  impression  of  the  upper  surface,  in  a 


REVISION   OF  PALEOZOIC   STELLEROIDEA.  275 

fine-grained  micaceous  sandstone.  It  is  named  CribeUites  carbo- 
narius;  and  the  following  characters  are  observable:  Rays  five, 
rounded,  lanceolate,  five  times  as  long  as  the  disk,  ridged  in  the  center, 
covered  with  longitudinal  rows  of  reticulating  tubercles;  disk  small 
and  tuberculated.  The  disk  is  only  0.3  of  an  inch  in  diameter, 
while  the  rays  are  1.5  inches  in  length.  A  circular  impression  in  the 
disk  may  be  the  impression  of  the  Madreporiform  nucleus.  In  the 
form  of  this  Asteroid,  and  in  the  characters  observable,  it  is  similar 
to  Oribella  rosea,  Muller;  but  the  rays  are  proportionally  longer,  the 
disk  smaller,  and  the  tubercles  much  nearer  to  each  other  than  in 
the  recent  analogue.  The  sandstone  from  which  the  fossil  Sea-star 
was  obtained  lies  20  feet  above  the  Shilbottle  coal,  and  about  600 
feet  below  the  base  of  the  millstone  grit,  being  in  the  upper  part  of 
the  Mountain  Limestone  formation,  which,  in  Northumberland,  is 
about  3,000  feet  in  thickness.  In  this  sandstone  there  also  occur 
Strophomena  crenistria  and  the  remains  of  carboniferous  plants." 

Order  OPHIOCISTIA  Sollas. 

Ophiocistia  SOLLAS,  Quart.  Journ.  Geol.  Soe.  London,  vol.  55, 1899,  pp.  692,  700. — 
SOLLAS  and  SOLLAS,  Philos.  Trans.  Roy.  Soc.  London,  ser.  B,  vol.  202, 
1912,  pp.  214,  222. 

An  anomalous  order  of  free  Echinoderma. 

"The  Ophiocistia  are  Ophiuroidea  with  five  paired  series  of  append- 
ages, proceeding  from  the  ventral  surface  of  a  plated  test;  and  in 
which  vertebral  ossicles  are  absent  or  insignificant"  (p.  700). 

Contains  but  one  family,  the  Eucladiidse. 

Remarks. — That  Eudadia  and  Euthemon,  the  genera  belonging  to 
this  order,  are  ophiurids  is  said  to  be  apparent  from  the  following: 
"The  absence  of  any  openings  on  the  dorsal  surface,  and  of  any  indi- 
cation of  an  anus,  the  ventral  position  of  the  madreporite,  and  the 
sharp  distinction  of  the  arms  from  the  test."  On  the  other  hand, 
they  differ  from  all  known  ophiurids  in  several  important  particu- 
lars: 

"The  structure  and  disposition  of  the  arms  is  unlike  anything 
known  among  either  the  Ophiurse  or  the  Euryalse,  and  finds  no 
parallel  among  any  group  of  fossil  Ophiuroidea.  If  we  consider  the 
disposition  of  the  arms  first,  we  find  as  a  constant  character  among  the 
rest  of  the  Ophiuroidea  the  extension  of  five  of  these  appendages  over 
the  ventral  surface  of  the  disk  as  far  as  the  buccal  aperture;  the 
vertebral  ossicles  of  the  arms  are  also  serially  represented  in  the 
buccal  armature.  In  the  Euciadiidae  also  the  arms  are  given  off 
from  the- ventral  surface  of  the  test,  and  the  first  pair  have  their 
origin  in  the  outer  distal  angle  of  the  jaws;  if,  however,  we  are  to 
regard  the  serial  arms  of  Eucladiidse  as  the  free  extremities  of  lateral 


276  BULLETIN  88,   UNITED  STATES   NATIONAL   MUSEUM. 

branches  given  off  in  pairs  from  a  median  hypothetical  arm,  then  we 
must  admit  that  the  branching  takes  place  within  the  test  to  an  extent 
otherwise  unknown  within  the  class.  If  we  turn  next  to  the  structure 
of  the  arms,  we  find  no  less  striking  peculiarities.  No  decisive 
evidence  exists  to  prove  that  vertebral  ossicles  are  present,  but  if 
they  are  they  must  be  out  of  all  proportion  small  compared  with  the 
lumen  of  the  arm.  Since  the  cavity  of  the  arm  is  almost  entirely 
unoccupied  by  skeletal  structures,  the  question  naturally  arises  as 
to  the  nature  of  the  soft  parts  which  it  contained.  The  distal  arms 
are  so  large  that  they  might  well  have  afforded  room  for  extensions 
of  the  digestive  viscera  from  the  test.  The  absence  of  visible  aper- 
tures in  the  arms  is  another  very  puzzling  feature,  and  one  is  almost 
tempted  to  inquire  whether  the  paired  appendages  are  to  be  compared 
with  arms  at  all. 

"The  nature  of  the  buccal  armature  is  very  different  from  that 
of  any  other  Ophiuroid,  though  there  is  a  certain  amount  of  corre- 
spondence in  the  paired  structure  of  its  five  pieces.  The  absence  of 
any  opening  that  could  be  taken  for  bursal  apertures  is  noteworthy." 

Family  EUCLADIID^E  Gregory. 

Eudadiidse  GEEGORY,  Proc.  Zool.  Soc.  London  for  1896,  1897,  p.  1040.— SOLLAS, 
Quart.  Journ.  Geol.  Soc.  London,  vol.  55,  1899,  p.  692.— STURTZ,  Verh. 
naturh.  Ver.  preuss.  Rheinl.,  etc.,  vol.  56,  1900,  p.  204. — SCHONDORF,  Jahrb. 
nassauisch.  Ver.  Naturk.,  Wiesbaden,  vol.  63,  1910,  p.  236. 

Contains  the  genera: 
Eudadia  Woodward. 
Euthemon  Sollas. 

Genus  EUCLADIA  Woodward. 
Plates  37,  38. 

Eudadia  johnsoniH.  WOODWARD,  Geol.  Mag.,  vol.  6,  1869,  p.  241,  pi.  8.— ZITTEL, 
Handb.  Pal.,  vol.  1,  1879,  p.  443. — STURTZ,  Verh.  naturh.  Ver.  preuss. 
Rheinl.,  etc.,  vol.  50,  1893,  p.  30. — GREGORY,  Proc.  Zool.  Soc.  London  for 
1896,  1897,  p.  1040,  fig.  6  on  p.  1041.— SOLLAS,  Quart.  Journ.  Geol.  Soc.  Lon- 
don, vol.  55,  1899,  p.  692. — STURTZ,  Verh.  naturh.  Ver.  preuss.  Rheinl.,  etc., 
vol.  56,  1900,  p.  183.— SCHONDORF,  Jahrb.  nassauisch.  Ver.  Naturk.,  Wies- 
baden, vol.  62, 1909,  p.  47;  vol.  63, 1910,  p.  240.— SOLLAS  and  SOLLAS,  Philos. 
Trans.  Roy.  Soc.  London,  ser.  B,  vol.  202,  1912,  pp.  214,  222.— SPENCER, 
Mon.  Brit.  Pal.  Asterozoa,  pt.  1  (Palseontogr.  Soc.  for  1913),  1914,  p.  50. 

This  genus  has  seven  pairs  of  arms  in  each  radius,  or  35  in  all. 
These  are  covered  with  finely  scaly  integument. 

Genoholotype. — E.  johnsoni  Woodward  (citations  as  above),  Lower 
Ludlow  formation,  at  Sedgley,  near  Dudley,  England.  Other  species 
are  E.  woodwardi  Sollas,  also  from  the  Lower  Ludlow,  at  Leintwar- 
dine,  England,  and  E.  f  leecheri,  new  species,  from  the  Lower  Devonic 
Coeymans  limestone,  New  York. 


REVISION   OF   PALEOZOIC   STELLEEOIDEA.  277 

EUCLADIA  WOODWARDI  Sollas. 

Plate  37,  figs.  1,  2. 

Eucladia  woodwardi  SOLLAS,  Quart.  Journ.  Geol.  Soc.  London,  vol.  55,  1899,  p. 
695,  figs.  1  and  2  on  p.  694. 

Original  description. — Ten  specimens  "  agree  in  presenting  five 
paired  series  of  appendages,  proceeding  from  the  ventral  surface 
of  the  body,  which  now  possesses  a  more  or  less  oval  outline.  The 
specimens  are  all  of  nearly  the  same  size,  the  central  body  measur- 
ing about  2  by  3  cm.,  the  longest  arms  2.5  cm.  in  length,  and  about 
3  mm.  in  breadth  where  broadest.  Not  more  than  four,  possibly 
only  three,  pairs  of  arms  can  be  traced  in  connection  with  each 
radius,  but  an  additional  pair  may  have  existed  close  to  the  buccal 
armature,  and  have  since  become  crushed  out  of  recognition. 

"  TTie  dorsal  surface  [fig.  1]. — This  is  completely  covered  by  nu- 
merous rounded  polygonal  or  irregular  scales,  about  0.2  mm.  thick 
and  not  exceeding  5  mm.  in  diameter;  their  surface  is  richly  granu- 
lated. They  are  not  arranged  according  to  any  discoverable  law, 
though  there  may  be  a  tendency  to  run  parallel  with  the  ambitus. 
In  their  present  state  they  overlap  each  other  to  such  an  extent 
that  one  plate  may  be  half  concealed  by  another;  no  doubt  they 
were  imbricated  during  life,  but  the  excessive  overlap  now  presented 
is  probably  due  in  part  to  crushing.  The  direction  of  the  imbrica- 
tion is  upward,  that  is,  in  the  direction  opposite  to  that  of  tiles  on 
a  roof,  and  thus  resembles  the  imbrication  of  the  dorsal  surface  of  a 
recent  Ophiuroid.  The  plates  are  all  of  the  same  nature,  and  there 
are  no  openings  on  the  dorsal  surface. 

"  The  ventral  surface  [fig.  2]. — In  the  center  the  powerful  buccal 
armature  is  a  very  conspicuous  object.  It  consists  of  five  pairs 
of  strong  plates  or  ossicles,  precisely  similar  in  their  form  and 
arrangement  to  those  of  Eiicladia  johnsoni.  Around  the  armature 
are  numerous  small  plates,  irregularly  disposed;  from  their  form 
and  size  these  may  be  regarded  as  elements  of  the  test,  though  they 
may  possibly  include  remains  of  crushed  arms.  If,  as  judging 
from  analogy  we  might  suppose,  minute  arms  proceeded  from  the 
outer  angles  of  the  jaws,  they  have  since  disappeared. 

"  Outside  the  irregularly  scattered  small  plates  larger  ones  are 
seen  arranged;  along  the  five  radii  these  are  escutcheon-shaped, 
imbricated,  and  form  a  single  series  of  three.  Distally,  each  plate 
is  produced  into  three  processes,  a  single  median  and  two  lateral; 
the  angle  formed  by  the  side  of  the  plate  and  each  lateral  process 
is  rounded  and  thickened  to  form  one  side  of  a  circular  aperture 
for  the  passage  or  insertion  of  the  arm,  and  the  other  half  of  the 
aperture  is  completed  by  the  thickened  margin  of  a  similarly  exca- 


278  BULLETIN   88,   UNITED   STATES    NATIONAL    MUSEUM. 

vated  adjacent  or  adradial  plate.  The  adradial  plates  form  a  pair, 
which,  meet  in  the  interradius.  The  arrangement  is  similar  to  that 
which  occurs  in  the  genus  EutTiemon,  to  be  next  described;  in  the 
latter,  however,  the  plates  are  not  overlapping,  but  tesselated. 
The  overlapping  of  the  plates  is  less  on  the  ventral  than  on  the 
dorsal  side,  a  difference  which  is  probably  due  to  the  less  amount 
of  displacement  suffered  by  the  ventral  plates;  and  this,  again,  is 
explicable  on  the  assumption  that  the  ventral  surface  was  flatter 
than  the  dorsal. 

"  The  arms. — The  arms  of  this  species  do  not  exhibit  that  marked 
increase  in  size,  as  their  position  in  the  series  becomes  more  distal, 
which  is  characteristic  of  Eucladia  johnsoni.  Their  average  length 
is  25  mm.  Near  their  tapering  extremities  the  arms  present  on  both 
dorsal  and  ventral  surface  three  plates,  two  of  which  are  lateral 
and  one  median,  recalling  the  characteristic  plating  of  an  Ophiuroid 
arm;  but  nearer  the  origin  the  number  of  conspicuous  plates  on 
either  surface  is  increased  to  four  or  even  more,  and  smaller  supple- 
mental plates  are  inserted  between  them  in  a  manner  precisely 
similar  to  that  already  described  hi  the  case  of  Eucladia  johnsoni. 
The  larger  plates,  swollen  at  first  and  becoming  mucronate  finally, 
are  produced  into  a  short  awn-like  termination. 

"A  search,  which  proved  unsuccessful,  was  made  for  some  trace 
of  vertebral  ossicles;  had  these  structures  been  present  originally, 
they  must  either  have  been  very  small  or  some  traces  would  still 
be  discernible.  In  Lapworihura,  which  occurs  in  the  same  rocks, 
the  vertebral  ossicles  are  the  most  obvious  elements  in  the  brachial 
skeleton. 

"The  distinction  of  Eucladia  woodwardi  from  E.  johnsoni  rests 
on  the  smaller  number  of  arms  possessed  by  the  former  and  the 
closer  approach  of  these  to  equality  in  dimensions.  The  speci- 
men selected  as  the  'type'  is  exhibited  in  the  Oxford  University 
Museum,  and  bears  a  label  stating  where  its  description  may  be 
found." 

Formation  and  locality. — In  the  Lower  Ludlow,  Leintwardine, 
England. 

EUCLADIA  (?)  BEECHERI,  new  species. 
Plate  38,  fig.  1. 

As  this  problematic  fossil  is  of  considerable  interest,  it  is  thought 
best  to  make  it  known  in  this  work,  even  though  the  preservation 
is  not  good.  The  general  characters  are  easily  seen  in  the  specimen, 
however,  and  much  better  than  can  be  shown  by  photography,  but 
in  detail  very  little  can  be  made  out.  The  fossil  lies  in  a  dense 
dark  limestone  beneath  the  surface  of  a  parting  between  two  beds 


EEVISION   OF   PALEOZOIC   STELLEEOIDEA.  279 

of  stone.  Originally  but  a  few  of  the  arms  showed,  and  it  was  at 
once  seen  by  the  late  Professor  Beecher  that  he  had  found  some- 
thing very  different  from  a  crinid.  He  bestowed  a  great  deal  of 
skill  and  labor  on  the  fossil  later  on,  bringing  it  out  to  its  present 
relief,  and  in  this  condition  it  has  remained  since  1901,  the  year 
of  its  collection.  It  seemed  to  both  Professor  Beecher  and  the  writer 
that  it  was  an  early  form  of  branching  or  basket  star,  recalling  the 
living  AstropJiyton.  Recently,  since  reading  the  work  of  Sollas  on 
Eudadia,  it  became  clear  that  this  view  could  not  be  maintained. 

The  specimen  seemingly  shows  the  ventral  side. 

The  disk  is  large  and  distinctly  pentagonal,  and  from  its  five  cor- 
ners radiate  the  more  or  less  coiled  rays.  Disk  composed  of  de- 
cidedly thick  plates,  apparently  closely  adjoining,  but  then-  arrange- 
ment is  too  much  disturbed  and  crystalline  to  make  out.  R  =  ?  about 
13  mm.,  r)=10.5  mm.,  B,  to  edge  of  rays  averaging  22  mm. 

Bays  apparently  completely  circular  in  outline  and  covered  by 
an  abundance  of  imbricating  scales,  of  which  there  are  about  five 
across  the  diameter  of  a  ray.  The  average  diameter  of  the  rays 
is  between  1.5  and  2  mm.  As  the  rays  are  crystalline  the  nature 
of  the  internal  skeleton  can  not  be  made  out  further  than  that 
there  are  vertebrae  present.  Each  radius  appears  to  have  4  pairs 
of  arms,  there  being  therefore  40  in  all,  but  then*  situation  in  the 
disk  and  how  they  appear  during  growth  cannot  be  made  out.  Three 
pairs  are  of  the  same  size  throughout,  while  the  fourth  pair,  which 
lies  upon  the  others,  seems  to  be  about  half  grown,  and  if  there  is  no 
decided  distortion  of  the  disk  plates,  these  appeared  alternately, 
first  on  one  side  and  then  on  the  other.  In  Eudadia  the  30  rays 
are  practically  all  alike,  but  in  EutJiemon  the  20  arms  are  equally 
divided  between  full  and  half  grown  ones. 

Formation  and  locality. — From  about  the  middle  of  the  Coeymans 
limestone  of  the  Helderbergian  (Lower  Devonic),  at  Jerusalem  Hill, 
Litchfield,  Herkimer  County,  New  York.  The  holotype  is  hi  the 
Peabody  Museum  of  Yale  University. 

Genus  EUTHEMON   Sollas. 

Euthemon  igerna  SOLLAS,  Quart.  Journ.  Geol.  Soc.  London,  vol.  55,  1899,  p.  696, 
figs.  3  and  4  on  p.  698.— SOLLAS  and  SOLLAS,  Philos.  Trans.  Roy.  Soc.  Lon- 
don, ser.  B,  vol.  202,  1912,  p.  222. 

This  genus  is  very  similar  to  Eudadia ,  but  differs  at  once  in  having 
but  4  arms  in  each  radius,  or  20  in  all;  10  of  these  are  more  than 
twice  as  long  (12  to  13  mm.)  as  the  others  (5  mm.). 

GenoJiolotype  and  only  species. — E.  igerna  Sollas,  from  the  Wenlock 
limestone,  Croft  farm,  Malvern,  England. 


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284  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

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( Onychas  ter,  0.  flexilis . ) 
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Acad.  Nat.  Sci.,  Philadelphia,  for  1869,  vol.  21,  pp.  67-83. 
18696.  Descriptions  of  new  Carboniferous  fossils  from  the  Western  States.    Proc. 

Acad.  Nat.  Sci.,  Philadelphia,  for  1869,  vol.  21,  pp.  137-172.    (Protaster  ? 

gregarius.) 

1873.  Palaeontology  of  Illinois.    Geol.  Surv.  Illinois,  vol.  5,  pp.  323-619,  pis.  1-32. 
MILLER,  S.  A. 

1878.  Description  of  a  new  genus  and  eleven  new  species  of  fossils.    Journ.  Cin- 

cinnati Soc.  Nat.  Hist.,  vol.  1,  pp.  100-108,  pi.  3.   (Palseaster  longibrachi- 
atus,  P.  clarkei.) 

1879.  Description  of  twelve  new  fossil  species,  and  remarks  upon  others.    Journ. 

Cincinnati  Soc.  Nat.  Hist.,  vol.  2,  pp.  104-118,  pis.  9, 10.     (Palseaster 
harrisi.} 

1880a.  Description  of  two  new  species  from  the  Niagara  group,  and  five  from  the 
Keokuk  group.    Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  2,  pp.  254-259, 
pi.  15.    (Palseaster  crawfordsvillensis.) 
18806.  Description  of  four  new  species  of  Silurian  fossils.    Journ.  Cincinnati  Soc. 

Nat.  Hist.,  vol.  3,  pp.  140-144,  pi.  4.    (Palseaster  miamiensis.) 
1880c.  Description  of  four  new  species  and  a  new  variety  of  Silurian  fossils,  and 
remarks  upon  others.    Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  3,  pp. 
232-236,  pi.  7.   (Palseaster  clarkana.) 

1881.  Description  of  some  new  and  remarkable  crinoids  and  other  fossils  of  the 
Hudson  River  group.  Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  4,  pp.  69-77, 
pi.  1.  (Palseaster  exculptus.) 

1882a.  Description  of  two  new  genera  and  eight  new  species  of  fossils  from  the 
Hudson  River  group,  with  remarks  upon  others.  Journ.  Cincinnati  Soc. 
Nat.  Hist.,  vol.  5,  pp.  34-44,  pis.  1,  2.  (Tseniaster  elegans.) 

18826.  Description  of  three  new  species,  and  remarks  upon  others.     Journ.  Cin- 
cinnati Soc.  Nat.  Hist.,  vol.  5,  pp.  116-117,  pi.  5.  (Protaster  miamiensis.) 
1884.  Description  of  a  beautiful  star  fish  and  other  fossils.    Journ.  Cincinnati  Soc. 

Nat.  Hist.,  vol.  7,  pp.  16-20,  pi.  4.   (Palseaster  magnificus.) 
1889.  North  American  geology  and  palaeontology.   First  appendix,  1892;  Second 

appendix,  1897. 

1892.  Palaeontology.    Seventeenth  Rept.  Geol.  Surv.  Indiana,  pp.  611-705,  pis. 
1-20;  Advance  extras,  1891.    (Onychaster  asper,  0.  confragosiis,  and   0. 
demissus.} 
MILLER,  S.  A.,  and  DYER,  C.  B. 

1878a.  Contributions  to  palaeontology.    Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  1, 
pp.  24-39,  pis.  1-2.      (Palseaster  simplex,  P.  spinulosus,  Palseasterina 
approximata,  P.  speciosa,  Protaster  flexuosus.) 
18786.  Contributions  to  palaeontology,  No.  2.    Privately  printed.     (Palseaster 

dubius.) 
MILLER,  S.  A.,  and  GURLEY,  W.  F.  E. 

1891.  Description  of  some  new  genera  and  species  of  Echinodermata  from  the 
Coal  Measures  and  Subcarboniferous  rocks  of  Indiana,  Missouri,  and 
Iowa.  Sixteenth  Rept.  Geol.  Surv.  Indiana,  pp.  327-373,  pis.  1-10; 
Advance  extras,  1890.  (Schcenaster  legrandensis,  Aganaster.) 


REVISION"   OF   PALEOZOIC   STELLEROIDEA.  285 

MILLER,  S.  A.,  and  GURLEY,  W.  F.  E. — Continued. 

1897.  New  species  of  crinoids,  cephalopods,  and  other  Palaeozoic  fossils.  Bull. 
Illinois  State  Mus.  Nat.  Hist.,  No.  12.  (Palseaster  wykoffi.) 

MtJLLER,    J. 

1855.  In  ZEILER  and  WIRTGEN,  Bemerkungen  uber  die  Petrefacten  der  altern 
devonischen  Gebirge  am  Rheine,  etc.;  Verh.  d.  naturh.  Ver.  preuss. 
Rheinl.,  etc.,  vol.  12,  pp.  1-28,  pis.  l-9a.     (Asterias  rhenana.) 
MURCHISON,  R.  I. 
1854.  Siluria. 
NICHOLSON,  H.  A.,  and  ETHERIDGE,  R.,  JR. 

1880.  A  monograph  of  the  Silurian  fossils  of  the  Girvan  District  in  Ayrshire, 
fasc.  3.  (Tetraster,  T.  wyville-thomsoni.} 

D'ORBIGNY,  A.  D. 

1849.  Prodrome  de  Pal6ontologie,  vol.  1.     (Ccelaster  americanus.} 
PARKS,  W.  A. 

1908.  Notes  on  the  ophiuran  genus,  Protaster,  with  description  of  a  new  species. 

Trans.  Canadian  Inst.,  vol.  8,  pp.  363-372,  1  pi.     (Gives  summary  of 

history  of  genus.    P.  whiteavesianus.) 

QUENSTEDT,    F.    A. 

1876.  Petrefactenkunde  Deutschlands,  vol.  4,  Asteriden  und  Encriniden. 
RAYMOND,  P.  E. 

1912a.  On  two  new  Paleozoic  starfish  (one  of  them  found  near  Ottawa),  and  a  new 
crinoid.  Ottawa  Naturalist,  vol.  26,  pp.  77-81,  pi.  5,  2  text  figs. 
(Palxaster  f  wilsoni,  Schcenaster  f  montanus.) 

19126.  On  the  nature  of  the  so-called  "covering  plates"  in  Protopalseaster  narra- 
wayi.     Ottawa  Naturalist,  vol.  26,  pp.  105-108,  pi.  6. 

RlNGUEBERG,    E.    N.    S. 

1886.  New  genera  and  species  of  fossils  from  the  Niagara  shales.    Bull.  Buffalo 
Soc.  Nat.  Sci.,  vol.  5,   pp.   5-22,   pis.   1,2.     (Squamaster,  S.  echinatus, 
Protaster  stellifer,  Eugaster  condnnus.) 
ROEMER,  F. 

1863.  Neue  Asteriden  und  Crinoiden  aus  devonischem  Dachschiefer  von  Bunden- 
bach  bei  Birkenfeld.  Palaeontographica,  vol.  9,  pp.  143-152,  pis.  23- 
29.  (Aspidosoma  tischbeinianum,  Asterias  asperula,  A.  spinosissima, 
Helianthaster,  H.  rhenanus.) 

RUEDEMANN,    R. 

1912.  The  Lower  Siluric  shales  of  the  Mohawk  valley.    Bull.  N.  Y.  State  Mus., 

No.  162.     (Txniaster  schoharix.) 
SALTER,  J.  W. 

1857.  On  some  new  Palaeozoic  star-fishes.  Ann.  Mag.  Nat.  Hist.,  ser.  2,  vol.  20, 
pp.  321-334,  pi.  9.  (Palseocoma,  P.  marstoni,  P.  colvini,  P.  cygnipes, 
Bdellacoma.  B.  vermiformis,  Rhopalocoma,  R.  pyrotechnica,  Palseaster 
asperrimus,  P.  coronella,  Palasterina,  Protaster  miltoni,  P.  leptosoma.) 

1861.  Additional  notes  on  some  new  Palaeozoic  star-fishes.  Ann.  Mag.  Nat. 
Hist.,  ser.  3,  vol.  8,  pp.  484-486,  pi.  18,  figs.  9-11. 

1866.  On  the  fossils  of  North  Wales.    Mem.  Geol.  Surv.  Great  Britain,  vol.  3, 

App.,  pp.  240-381,  pis.  1-28.     (Palseaster  imbricatus.) 
SALTER,  J.  W.,  and  SOWERBY,  J.  de  C. 

1845.  In  SEDGWICK,  On  the  Older  Palaeozoic  (Protozoic)  rocks  of  North  Wales. 
Quart.  Journ.  Geol.  Soc.,  London,  vol.  1,  pp.    5-22.     (Ophmra  salteri 
and  Asterias  primseva  listed  in  table,  without  description.) 
SANDBERGER,  G.,  and  SANDBERGER,  F. 

1850-1856.  Die  Versteinerungen  des  rheinischen  Schichtensystems  in  Nassau. 
(Ccelaster,  C.  latiscutatus.) 


286  BULLETIN  88,  UNITED  STATES   NATIONAL   MUSEUM. 

SCHONDORF,  F. 

1907a.  Ueber  einen  fossilen  Seestern  Spanister  latiscutatus  Sandb.  spec,  aus 
dem  Naturhistorischen  Museum  zu  Wiesbaden.  Jahrb.  nassauisch. 
Ver.  f .  Naturk. ,  Wiesbaden,  vol.  60,  pp.  17XM76, 3  text  figs.  (Spaniaster. ) 

19076.  Ueber  Archseasterias  rhenana  Joh.  Muller  und  die  Porenstellung  palao- 
zoischer  Seesterne.  Centralb.  f.  Mineral.,  etc.,  pp.  741-750,  6  text 
figs. 

1909a,  Palaozoische  Seesterne  Deutschlands.  I.  Die  echten  Asteriden  der 
rheinischen  Grauwacke.  Palseontographica,  vol.  56,  pp.  37-112,  text 
figs.,  pis.  7-11.  (Agalmaster,  A.  grandis,  A.  intermedius,  A.  miellensis, 
Rhenaster,  R.  schwerdi,  Trimeraster,  T.  parvulus,  Eifelaster,  E.  foll- 
manni,  Xenaster  dispar,  X.  elegans.) 

19096.  Die  Asteriden  des  russischen  Karbon.  Palseontographica,  vol.  56,  pp. 
323-338,  text  fig.,  pis.  23,  24. 

1909c.  Die  fossilen  Seesterne  Nassaus.  Jahrb.  nassauisch.  Ver.  f.  Naturk., 
Wiesbaden,  vol.  62,  pp.  7-46,  text  figs.,  pis.  2-5.  (Discusses  skeletal 
structure  of  asterids;  Miomaster,  M.  drevermanni.) 

1909rf.  Organization  und  Aufbau  der  Armwirbel  von  Ony chaster.  Jahrb.  nassau- 
isch.  Ver.  f.  Naturk.,  Wiesbaden,  vol.  62,  pp.  47-63,  pi.  6. 

1910a.  Ueber  einige  "Ophiuriden  und  Asteriden"  des  englischen  Silur  und  ihre 
Bedeutung  fiir  die  Systematik  palaozoischer  Seesterne.  Jahrb.  nassau- 
isch. Ver.  f.  Naturk.,  Wiesbaden,  vol.  63,  pp.  206-256,  text  figs.  (Im- 
portant for  classification.) 

19106.  Palaozoische  Seesterne  Deutschlands.  II.  Die  Aspidosomatiden  des 
deutschen  Unterdevon.  Palseontographica,  vol.  57,  pp.  1-63,  pis.  1-3. 
(Discusses  structure  and  systematics  of  group  in  much  detail.  Erects 
a  new  order,  Auluroidea.  Aspidosoma  goldfussi.  A.  roemeri.  A.  eifelense.) 

1910c.  Aspidosoma  schmidti  nov.  spec.  Der  erste  Seestern  aus  den  Siegener 
Schichten.  Jahrb.  k.  preuss.  geol.  Landesanst.  und  Bergakad.,  Berlin, 
vol.  29,  1908,  pt.  1,  pp.  698-708,  1  pi. 

1913a.  Palaeaster  eucharis  Hall  aus  dem  nordamerikanischen  Devon.  Jahrb. 
nassauisch.  Ver.  f.  Naturk.,  Wiesbaden,  vol.  66,  pp.  87-96,  text  figs. 
1,  2,  pi.  3,  figs.  1,  2. 

19136.  Ueber  Onychaster,  einen  Schlangenstern  aus  dem  Karbon.  Jahrb.  nas- 
sauisch. Ver.  f.  Naturk.,  Wiesbaden,  vol.  66,  pp.  97-116,  text  figs. 
1,  2,  pi.  3,  figs.  3-12. 

SCHUCHERT,  C. 

1914.  Fossilium  Catalogus,  I :  Animalia,  pars  3,  Stelleroidea  palaeozoica. 
SIMONOVITSCH,  S. 

1871.  Ueber  einige  Asterioiden  der  rheinischen  Grauwacke.  Sitzb.  d.  mat.- 
naturw.  Classe  d.  k.  Akad.  d.  Wiss..  Wien,  vol.  64,  Abt.  1.,  pp.  77-122, 
pis.  1-4.  (Xenaster,  X.  margaritatus,  X.  simplex,  Asterias  acuminatus, 
Aspidosoma  petaloides.} 

SOLLAS,  I.  B.  J. 

1913.  On  Onychaster,  a  Carboniferous  brittle-star.    Philos.  Trans.  Roy.  Soc. 

London,  ser.  B,  vol.  204,  pp.  51-62,  text  figs.  1-5,  pis.  8,  9. 
SOLLAS,  W.  J. 

1899.  Fossils  in  the  University  Museum,  Oxford:  I.  On  Silurian  Echinoidea  and 

Ophiuroidea.    Quart.  Journ.  Geol.  Soc.,  London,  vol.  55,  pp.  692-715, 

text  figs.    (Erects  new  order,  Ophiocistia.    Eudadia  woodwardi,  Euthe- 

mon,  E.  igerna.) 
SOLLAS,  W.  J.,  and  SOLLAS,  I.  B.  J. 

1912.  Lapworthura:  a  typical  brittle-star  of  the  Silurian  age.     Philos.  Trans. 

Roy.  Soc.  London,  ser.  B,  vol.  202,  pp.  213-232,  text  figs.  1-5,  pis.  9,  10. 

(Rhodostoma,  Protaster  groomi.) 


KEVISIOK   OF  PALEOZOIC   STELLEROIDEA.  287 

SPENCER,  J.  W. 

1884.  Niagara  fossils,  Pt.  3.    Bull.  Mus.  Univ.  State  Missouri,  No.  1,  pp.  52-61, 

pis.  7,  8.     (Palseaster  granti.} 
SPENCER,  W.  K. 

1914.  A  monograph  of  the  British  Palaeozoic  Asterozoa.    Pt.  1.    Palaeontogr.  Soc. 
for  1913;  pp.  1-56,  text  figs.  1-31,  pi.  1.    (Eoactis,  E.  simplex,  Uranaster 
elizx,  Aspidosoma  grayse,  Lapworthura  sollasi.) 
STSCHUROWSKY. 

1874.  Nachr.  d.  Moskauer  Gesell.  d.  Liebhaber  d.  Naturges.     (Asterias  montanus.) 

Not  seen. 
STURTZ,  B. 

1886a.  Ueber  palaozoische  Seesterne.    N.  Jahrb.  f.  Mineral.,  etc.,  vol.  2,  pp. 

142-154.     (Hallaster.) 

18866.  Beitrag  zur  Kenntniss palaozoischer  Seesterne.  Palseontographica,  vol.  32, 
pp.  75-98,  pis.  8-14.  (Ophiurella,  0.  primigenia,  Roemeraster,  R.  asperula, 
Astropecten  schluteri,  Eoluidia,  E.  decheni,  Protester acanthion,  P.  pri- 
mus, Fur  caster,  F.  palseozoicus,  Bundenbachia,  B.  beneckei,  B.  grandis, 
Palastropecten,  P.  zitteli,  Loriolaster,  L.  mirabilis,  Palasteriscus,  P. 
devonicus.) 

1890.  Neuer  Beitrag  zur  Kenntniss  palaozoischer  Seesterne.  Palseontographica, 
vol.  36,  pp.  203-247,  pis.  26-31.  (Echinasterella,  E.  sladeni,  Cheiropter- 
aster,  C.  giganteus,  Medusaster,  M.  rhenanus,  Palseostella,  P.  solida, 
Ophiurina,  0.  lymani,  Palseophiura,  P.  simplex,  Palasterina  follmanni. 
Describes  additional  material  of  forms  dealt  with  in  1886,  revises 
other  species,  discusses  structure,  systematics,  habits,  etc.,  of  Paleozoic 
ophiurids  and  asterids.) 

1893.  Ueber  versteinerte  und  lebende  Seesterne.  Verh.  naturh.  Ver.  preuss. 
Rheinl.,  etc.,  vol.  50,  pp.  1-92,  pi.  1.  (Salteraster,  Ophiura  rhenana, 
Palxnectria,  P.  devonica.) 

1900.  Ein  weiterer  Beitrag  zur  Kenntniss  palaozoigcher  Asteroiden.  Verh.  naturh. 
Ver.  preuss.  Rheinl.,  etc.,-  vol.  56,  pp.  176-240,  pis.  2-4.  (Reviews 
Gregory's  work  of  1896  and  gives  classification  of  Ophiuroidea  with 
definition  of  families.  Hisingeraster,  Trentonaster,  Hudsonaster,  Pseudo- 
palasterina,  Eophiurites,  Palseophiomyxa,  Palseospondylus,  Palxosolaster, 
P.  gregoryi,  Echinasterias,  E.  spinosus,  Echinodiscus,  E.  multidactylus, 
Echinostella,  E.  traquairi,  Jaekelaster,  J.  petaliformis.) 
THORENT. 

1838.  M^moire  sur  la  constitution  ge*ologique  de  la  partie  nord  du  Departe*ment 
de  1'Aisne.    Mem.  Soc.  ge"ol.  de  France,  vol.  3,  pp.  239-260,  pi.  22. 
(Asterias  constellata.) 
TRAUTSCHOLD,  H. 

1879.  Die  Kalkbriiche  von  Mjatschkowa,  Theil  3.    M^m.  Soc.  imp.  Nat.  Moscou, 
vol.  14,  pp.  101-180,  7  pis.     (Calliaster,  C.  mirus,  Stenaster  confluens.) 
TROOST,  G. 

1835.  Description  of  a  new  species  of  fossil  Asterias  (Asterias  antiqua).    Trans. 

Geol.  Soc.  Pennsylvania,  vol.  1,  pp.  232-235. 
ULRICH,  E.  0. 

1878.  Descriptions  of  some  new  species  of  fossils  from  the  Cincinnati  group; 

Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  1,  pp.  92-100,  pi.  4.    (Protasterina, 
P.fimbriata.) 

1879.  Descriptions  of  new  genera  and  species  of  fossils  from  the  Lower  Silurian 

about  Cincinnati.    Journ.  Cincinnati  Soc.  Nat.  Hist.,  vol.  2,  pp.  8-30, 
pi.  7.     (Palseaster  finei.) 
50601° — Bull.  88 — 15 19 


288  BULLETIN   88,   UNITED   STATES   NATIONAL    MUSEUM. 

VERRILL,  A.  E. 

1914.  Monograph  of  the  shallow-water  starfishes  of  the  North  Pacific  coast  from 
the  Arctic  Ocean  to  California.     Smithsonian  Institution,  Harriman 
Alaska  ser.,  vol.  14. 
WOODWARD,  H. 

1869.  On  Eucladia,  a  new  genus  of  Ophiuridae,  from  the  Upper  Silurian,  Dudley. 

Geol.  Mag.,  vol.  6,  pp.  241-245,  pi.  8.     (Eucladia,  E.  johnsoni.) 
1874.  Description  of  a  new  species  of  starfish  from  the  Devonian  of  Great  Ingle- 
bourne,  Harberton,  South  Devon.    Geol.  Mag.,  dec.  2,  vol.  1,  pp.  6-10, 
96,  238,  432.     (Helianthaster  filitiformis.} 
WORTHEN,  A.  W.,  and  MILLER,  S.  A. 

1883.  Descriptions  of  new  Carboniferous  Echinoderms.      Geol.  Surv.  Illinois, 
vol.  7,  pp.  327-331,  pi.  31.     (Compsaster,  C.  formosus,  Cholaster,  C.  pe- 
culiaris,  Tremataster,  T.  dijficilis.) 
WRIGHT,  T. 

1862.  A  monograph  on  the  British  fossil  Echinodermata  from  the  Oolitic  forma- 
tions, vol.  2,  pt.  1.    Palseontogr.  Soc.  for  1861.    (Contains  a  diagnosis  of 
nine  Paleozoic  genera  with  species.) 
1873.  On  a  new  genus  of  Silurian  Asteriadse.     Quart.  Journ.  Geol.  Soc.,  London, 

vol.  29,  p.  421.     (Trichotaster,  T.  plumiformis.) 
ZITTEL,  K.  von. 

1879.  Handbuch  der  Palaontologie,  vol.  1. 


EXPLANATION  OF  PLATES. 
PLATE  1. 

FIG.  1. — Rudsonaster  narrawayi  (Hudson)  (also  see  plates  2  and  4). 

A  greatly  enlarged  photograph  of  the  genoholotype  of  Protopalssaster 
narrawayi  Hudson.  The  inner  ventral  side  of  the  specimen  is  here  seen 
with  all  of  the  dorsal  skeleton  weathered  away  except  one  of  the  basal 
supramarginalia.  Note  the  well-preserved  oral  armature  and  in  places 
the  ambulacralia.  The  latter  are  the  "covering  plates"  of  Hudson. 

Photograph  by  Prof.  George  H.  Hudson. 

Middle  Ordovicic  (Black  River).    Ottawa,  Canada. 

Collection  of  Mr.  J.  E.  Narraway. 


PLATE  2. 

FIG.  1. — Hudsonaster  narrawayi  (Hudson)  (also  see  plates  1  and  4). 

A  photograph  X  6  of  the  actinal  side.    Note  the  five  long  spines  (tori) 
of  the  oral  armature. 

Middle  Ordovicic  (Black  River).     Kirkfield,  Ontario,  Canada. 

Collection  of  Peabody  Museum,  Yale  University. 
FIG.  2. — Hudsonaster  matutinus  (Hall)  (also  see  plates  3  and  5). 

A  photograph  X  3  of  three  specimens  showing  the  actinal  area  as  preserved 
on  a  piece  of  black  limestone. 

Middle  Ordovicic  (Trenton).    Rathbone  Brook,  near  Newport,  Her- 
kimer  County,  New  York. 

Collection  of  Museum  of  Comparative  Zoology,  Harvard  University 
(No.  26). 


PLATE  3. 

FIG.  1. — Hudsonaster  rugosus  (Billings). 

A  photograph  X  2  of  the  abactinal  area  of  a  cotype. 
Upper  Ordovicic  (Richmondian).    Charleton  Point,  Anticosti  Island, 
Gulf  of  St.  Lawrence,  Canada. 

Collection  of  the  Geological  Survey  of  Canada  (No.  1999). 
FIG.  2. — Hudsonaster  matutinus  (Hall)  (also  see  plates  2  and  5). 

A  retouched  photograph  X  2  showing  the  abactinal  side. 
Middle  Ordovicic  (Trenton).    Trenton  Falls,  New  York. 
Collection  of  the  Museum  of  Comparative  Zoology,  Harvard  University 
(No.  3). 
FIG.  3. — Hudsonaster  batheri,  new  species. 

A  diagram  X  3  of  the  actinal  side  made  from  a  wax  squeeze  by  Bather, 
now  in  the  United  States  National  Museum  (Cat.  No.  60601). 
Upper  Ordovicic.    Thraive,  Girvan,  Scotland. 

289 


290          '  BULLETIN   88,   UNITED   STATES   NATIONAL    MUSEUM. 

PLATE  4. 

FIG.  1. — Hudsonaster  narrawayi  (Hudson)  (also  see  plates  1  and  2). 

A  camera  lucida  drawing  X  8  of  the  actinal  side.  The  granules  are 
drawn  somewhat  too  strongly. 

Middle  Ordovicic  (Black  River).     St.  Paul,  Minnesota. 

Ulrich  collection  of  the   United  States  National   Museum  (Cat.  No. 
60602). 
FIG.  2. — Hudsonaster  milleri,  new  species. 

A  diagram,  considerably  enlarged,  of  an  axillary  area  from  the  actinal 
side. 

Middle  Ordovicic  (Trenton).    Fayette  County,  Kentucky. 

Collection  of  the  State  University  of  Kentucky. 
FIG.  3. — Mesopalxaster  (?)  lanceolatus,  new  species. 

Camera  lucida  drawing  of  one  ra>  from  the  actinal  area,  X  2.  The 
central  furrow  in  the  ambulacrum  is  decidedly  V-shaped. 

Upper  Ordovicic  (Utica).    Near  Rome,  New  York. 

Collection  of  Peabody  Museum,  Yale  University. 
FIG.  4. — Australaster  giganteus  (Etheridge). 

An  axillary  area  and  part  of  two  rays  somewhat  reconstructed  from  the 
original  figure.  Natural  size.  Note  the  single  very  large  axillary  plate, 
the  enlarging  adambulacrals,  and  the  diminishing  inframarginals. 

"Permo-Carboniferous"  (Lower  Marine).  Parley,  Northumberland 
County,  New  South  Wales. 

Collection  of  the  Mining  and  Geological  Museum,  Sydney. 

PLATE  5. 

FIGS.  1  and  2. — Hudsonaster  matutinus  (Hall)  (also  see  plates  2  and  3). 

1.  Camera  lucida  drawing  X  3.5  of  the  actinal  side  of  one  of  the  speci- 
mens photographed  on  plate  2,  fig.  2. 

Middle  Ordovicic  (Trenton).    Near  Newport,  New  York. 
Collection  of  Museum   of   Comparative   Zoology,  Harvard   University 
(No.  26). 

2.  Camera  lucida  drawing  X  4.5  of  the  abactinal  area  of  a  specimen  in 
which  the  ossicles  are  somewhat  displaced. 

Middle  Ordovicic  (Trenton).    Lachine,  near  Montreal,  Canada. 
Collection  of  the  United  States  National  Museum  (Cat.  No.  60603). 
Collected  by  W.  R.  Billings. 

PLATE  6. 

FIGS.  1  and  2. — Hudsonaster  incomptus  (Meek). 

1.  Camera  lucida  drawing  X  4  of  the  actinal  side. 

Upper  Ordovicic  (Richmondian).    Near  Waynesville,  Ohio. 

Harris  collection  of  the  United  States  National  Museum  (Cat.  No.  40882). 

2.  Camera  lucida  drawing  X  4  of  the  abactinal  area  in  a  well  preserved 
specimen.    The  anal  opening  may  have  been  in  the  first  circle  of  small 
plates  adjacent  to  the  centro-dorsal  piece  and  in  the  same  interradius  as 
the  madreporite. 

Upper  Ordovicic  (Richmondian).    Near  Waynesville,  Ohio. 

Harris  collection  of  the  United  States  National  Museum  (Cat.  No.  40882). 


REVISION   OF   PALEOZOIC   STELLEEOIDEA.  291 

PLATE  7. 

FIGS.  1-4. — Palseaster  niagarensis  Hall. 

1.  Camera  lucida  drawing  X  4  of  the  abactinal  side  in  its  present 
preservation.    Holotype. 

2.  Abactinal  side  of  theholotype  restored,  X  4.    The  drawing  probably 
has  too  many  accessory  disk  pieces. 

3.  Camera  lucida  drawing  X  4  of  the  a'ctinal  side  of  one  of  the  rays  of 
the  holotype.    Since  this  drawing  was  made  the  rock  in  the  ambulacral 
furrow  has  been  dug  away  down  to  the  ambulacral  plates,  which  are 
small  and  deep-seated. 

4.  A  few  of  the  inframarginals  and  supramarginals  from  the  abactinal 
side  to  show  the  smooth  central  areas  surrounded  by  granular  borders,  X  4. 
Siluric  (Rochester  shale).    Lockport,  New  York. 
Collection  of  Cornell  University  (No.  7331). 
FIG.  5. — Mesopalseaster  find  (Ulrich)  (also  see  plate  9). 

Camera  lucida  drawing  X  16  of  one  of  the  rays.    The  ossicles  are  always 
more  or  less  displaced  in  this  species. 

Upper  Ordovicic  (Eden  shales).    Cincinnati,  Ohio. 

Ulrich  collection  of  the  United  States  National  Museum  (Cat.  No.  60604). 

PLATE  8. 

FIGS.  1  and  2. — Mesopalseaster  shafferi  (Hall). 

1.  Camera  lucida  drawing  X  8  of  the  abactinal  side  of  a  one-third 
adult-sized  specimen.    As  the  medial  disk  pieces  are  displaced  in  the 
individual,  they  are  here  drawn  in  in  their  probable  natural  arrangement 
all  should  be  pointed  like  the  central  disk  plate. 

Upper  Ordovicic  (Maysvillian,  Corryville  member).    Cincinnati,  Ohio. 
Vaupel  collection  of  the  United   States  National  Museum  (Cat.  No. 
60605). 

2.  Camera  lucida  drawing  X  3  of  the  actinal  area  of  a  mature  indi- 
vidual. 

Upper  Ordovicic  (Kichmondian).    Waynesville,  Ohio. 
Harris   collection  of  the  United   States  National  Museum  (Cat.  No. 
59391). 
FIG.  3. — Miomaster  drevermanni  Schondorf. 

Actinal  side  as  reconstructed  by  Schondorf.    Natural  size. 
Lower  Devonic  (Upper  Coblenzian).    Miellen,  Germany. 

PLATE  9. 

FIG.  I.— Mesopalseaster  (?)  parviusculus  (Billings). 

Camera  lucida  drawing  X  5  of  a  gutta-percha  squeeze  of  the  holotype, 
actinal  side. 

Siluric  (Lower  Arisaig).   Arisaig,  Nova  Scotia. 

Original  at  McGill  University;  gutta-percha  squeeze  in  United  States 
National  Museum  (Cat.  No.  60620). 
FIG.  2. — Mesopalseaster  (?)  cataractensis,  new  species. 

Photograph  X  3  of  the  well-preserved  holotype. 

Siluric  (Cataract  formation).     Hamilton,  Ontario. 

Collection  of  the  Hamilton  Natural  History  Society. 
FIG.  3.— Mesopalseaster  (?)  granti  (Spencer). 

Photograph  X  2  of  a  specimen  showing  the  dorsal  side. 

Siluric  (Cataract  formation).    Hamilton,  Ontario. 

Collection  of  Peabody  Museum,  Yale  University. 


292  BULLETIN  88,  UNITED  STATES   NATIONAL   MUSEUM. 

FIG.  4. — Mesopalseaster  intermedius,  new  species. 

Photograph  X  3  of  the  holotype.    Between  the  two  rays  lies  an  arm  of 
a  crinid,  giving  the  impression  that  this  form  has  a  large  disk. 
Upper  Ordovicic  (Maysvillian).    Cincinnati,  Ohio. 
Collection  of  the  University  of  Chicago  (No.  9575). 
FIG.  5. — Mesopalseaster  finei  (Ulrich)  (also  see  plate  7). 

Ulrich's  original  figures.    Fig.  5,  one  of  the  cotypes  from  the  abactinal 
side  X  2;  fig.  5a,  the  madreporite  X  6;  fig.  56,  a  ray  from  the  actinal  side  X  3. 
Upper  Ordovicic  (Eden).    Cincinnati,  Ohio. 

Ulrich  collection  of  the  United  States  National  Museum  (Cat.  No.  60604). 
FIG.  6. — Mesopalseaster  caractad  (Gregory)  (also  see  plate  11). 

Retouched  photograph  X  3  of  a  wax  squeeze  by  Bather,  now  in  the 
United  States  National  Museum  (Cat.  No.  60606).    Actinal  area. 
Ordovicic  (Caradoc).    Church  Stretton,  England. 

PLATE  10. 

FIGS.  1  and  2. — Mesopalseaster  clarki  (Clarke  and  Swartz). 

1.  Drawing  of  the  actinal  side  of  the  holotype  X  1.5. 

2.  Abactinal  area  X  1.5.    Note  the  few  accessory  pieces  in  the  angles 
between  the  radials. 

Upper  Devonic  (Chemung).    Near  Oakland,  Maryland. 
Collection  of  the  Maryland  Geological  Survey. 

PLATE  11. 

FIG.  1. — Mesopalxaster  caractad  (Gregory)  (also  see  plate  9). 

Retouched  photograph  X  3  of  a  wax  squeeze  by  Bather,  now  in  the 
United  States  National  Museum  (Cat.  No.  60606).    Abactinal  area. 

Ordovicic  (Caradoc).   Church  Stretton,  England. 
FIG.  2. — Devonaster  chemungensis,  new  species. 

Photograph  of  the  natural  mold  of  the  actinal  side  of  the  holotype, 
natural  size. 

Upper  Devonic  (Chemung).    "Central  Pennsylvania." 
CoUection  of  Columbia  University  (No.  6228G). 

PLATE  12. 

FIGS.  1  and  2. — Spaniaster  latiscutatus  (Sandberger). 

1.  Abactinal  side. 

2.  Actinal  side. 
After  Schondorf . 

Lower  Devonic.    Germany. 
FIGS.  3-5. — Devonaster  eucharis  (Hall). 

3.  Abactinal  side,  natural  size,     a,  the  madreporite.   After  Hall. 

4.  Actinal  side,  natural  size.     After  Hall.     The  tiny  ambulacral  plates 
should  have  been  drawn  as  opposite  one  another  and  not  alternate. 

5.  Hall's  diagram  (3a)  of  the  actinal  plate  arrangement.    The  ambu- 
lacrals  are  incorrectly  drawn,  as  their  arrangement  is  opposite  and  not 
alternate,     a,  ambulacralia;  aa,  adambulacralia;  m,  inframarginalia;  o, 
pairs  of  oral  armature  ossicles;  p,  podial  openings,  but  drawn  a  little  too 
large;  tm,  the  single  interbrachial  axillaries. 

Middle  Devonic  (Hamilton).    Near  Hamilton,  New  York. 


REVISION   OF   PALEOZOIC    STELLEROIDEA.  293 

PLATE  13. 

FIGS.  1  and  2. — Promopalseaster  wilsoni  (Raymond). 

1.  Photograph  X  1.5  of  the  holotype,  showing  the  abactinal  side. 

2.  One  of  the  rays  of  the  holotype  X  3. 

Middle  Ordovicic  (Lowville).   City  View,  Ottawa,  Canada. 

Collection  of  Miss  A.  E.  Wilson. 
FIG.  3. — Promopalseaster  prenuntius,  new  species  (also  see  plate  15). 

Photograph,  natural  size,  of  the  actinal  side  of  the  holotype. 

Middle  Ordovicic  (Lower  Trenton).   Frankfort,  Kentucky. 

Collection  of  the  State  University  of  Kentucky. 
FIG.  4. — Anorthaster  miamiensis  (Miller)  (see  also  plate  20). 

Retouched  photograph,  natural  size,  of  the  actinal  side  of  the  holotype. 

Upper  Ordovicic  (Richmondian).   Waynesville,  Ohio. 

Harris  collection  of  the  United  States  National  Museum  (Cat.  No. 
40880). 
FIG.  5. — Neopalseaster  crawfordsvillensis  (Miller)  (see  also  plate  23). 

Retouched  photograph,  natural  size,  of  the  holotype,  showing  the  abac- 
tinal area. 

Mississippic  (Keokuk).    Crawfordsville,  Indiana. 

Harris  collection  of  the  United  States  National  Museum  (Cat.  No.  60607). 

PLATE  14. 

FIGS.  1  and  2. — Promopalseaster  speciosus  (Meek)? 

Reproduction,  natural  size,  of  the  original  lithograph  of  "Asterias  prir 
mordialis."    Probably  the  young  of  P.  speciosus. 

Upper  Ordovicic  (Maysvillian).    Cincinnati,  Ohio. 

The  specimen  is  now  lost. 
FIGS.  3  and  4. — Promopalseaster  speciosus  (Meek)  (also  see  plate  15). 

Photographs,  natural  size,  of  the  abactinal  and  actinal  sides  of  the 
holotype. 

Upper  Ordovicic  (Maysvillian).    Cincinnati,  Ohio. 

Dyer  collection  of   the  Museum  of   Comparative  Zoology,  Harvard 
University  (No.  22). 


PLATE  15. 

FIGS.  1-4. — Promopal&easter  speciosus  (Meek)  (also  see  plate  14). 

1.  Camera  lucida  drawing  X  4  of  an  interbrachial  area. 

2.  Camera  lucida  drawing  X  4  across  a  ray  at  about  its  mid-length. 
From  the  actinal  side,  showing  the   ambulacrals,  podial   openings, 

adambulacrals,  inframarginals,  and  supramarginals. 

3.  Two  adambulacral  spines  near  oral  region,  X  7. 

4.  A  part  of  the  abactinal  area  of  a  ray  near  its  mid-length,  X  2.5. 
All  drawn  from  the  holotype. 

Upper  Ordovicic  (Maysvillian).     Cincinnati,  Ohio. 
Dyer  collection  of  the  Museum  of  Comparative  Zoology,  Harvard  Uni- 
versity (No.  22). 
FIG.  5. — Promopalseaster  prenuntius,  new  species  (also  see  plate  13). 

Diagram  of  the  actinal  interbrachial  plate  arrangement. 


294  BULLETIN   88,   UNITED   STATES   NATIONAL   MUSEUM. 

FIGS.  6-8. — Promopalseaster  bellulus,  new  species  (also  see  plates  16  and  18). 

6.  Camera  lucida  drawing  X  4  of  an  interbrachial  area.     The  adambu- 
lacrals  are  in  natural  position,  but  the  interbrachial  axillaries  and  the 
inframarginals  are  somewhat  displaced.     Taken  from  the  specimen  on 
plate  16,  fig.  1. 

7.  Camera  lucida  drawing  X  7  of  the  abactinal  area  of  a  ray.     The 
ossicles  are  all  displaced,  but  originally  they  were  united  in  a  spicular 
and  partially  overlapping  mesh. 

8.  Madreporite  X  7. 

Upper  Ordovicic  (Richmondian).    Waynesville,  Ohio. 
Harris  collection  of  the  United  States  National  .Museum  (Cat.    No. 
40879). 

PLATE  16. 

FIG.  1. — Promopalseaster  bellulus,  new  species  (also  see  plates  15  and  18). 

Retouched  photograph,  natural  size,  of  the  actinal  side.  The  specimen 
is  in  limestone. 

Upper  Ordovicic  (Richmondian).    Waynesville,  Ohio. 

Harris  collection  of  the  United  States  National  Museum  (Cat.  No. 
40879). 
FIG.  2. — Promopalseaster  spinulosus  (Miller  and  Dyer)  (also  see  plates  17  and  18). 

Retouched  photograph,  natural  size,  of  the  actinal  side  of  the  holotype 
of  Palseaster  longibrachiatus  Miller.  The  well-preserved  columns  are  the 
inframarginals,  but  in  places  some  of  the  adambulacrals  are  also  shown. 

Upper  Ordovicic  (Richmondian).    Near  Clarksville,  Ohio. 

Harris  collection  of  the  United  States  National  Museum  (Cat.  No. 
40881). 

PLATE  17. 

FIGS.  1  and  2. — Promopalseaster  spinulosus  (Miller  and  Dyer)  (also  see  plates  16  and 

18). 

Retouched  photographs  X  3  of  the  actinal  and  abactinal  sides  of  the 
holotype. 

Upper  Ordovicic  (Richmondian).    Probably  near  Waynesville,  Ohio. 
Dyer  collection  of  the   Museum  of  Comparative  Zoology,   Harvard 
University  (No.  16). 

PLATE  18. 

FIGS.  1-3. — Promopalseaster  spinulosus  (Miller  and  Dyer)  (also  see  plates  16  and  17). 

1.  Camera  lucida  drawing  X  2,  somewhat  restored,  of  the  holotype 
of  Palseaster  longibrachiatus  Miller. 

2.  Camera  lucida  drawing  X  7  of  the  abactinal  area  of  a  ray  near  its 
base.    Shows  the  large  infra-  and  supramarginals  and  ambital  pieces. 
Center  of  ray  has  spicular  ossicles. 

3.  Madreporite  X  7. 

Upper  Ordovicic  (Richmondian).    Near  Clarksville,  Ohio. 
Harris  collection  of  the   United   States   National  Museum  (Cat.   No. 
40881). 


REVISION   OF   PALEOZOIC   STELLEEOIDEA.  295 

FIGS.  4  and  5~Promopalseaster  bellulus,  new  species  (also  see  plates  15  and  16). 

4.  Adambulacralia  and  their  spines,    X   7.    The  ambulacrum  lies  to 
the  left. 

5.  A  few  abactinal  spines,  X  7. 

Upper  Ordovicic  (Richmondian).    Waynesville,  Ohio. 

Harris  collection  of  the  United  States   National  Museum  (Cat.  No. 
40879). 
FIG.  G.—Promopalseaster  wyloffi,  (Miller  and  Gurley)  (also  see  plate  19). 

Diagram  X  3.5  of  one  of  the  interbrachial  areas. 

From  the  holotype. 

Upper  Ordovicic  (Richmondian).    Near  Madison,  Indiana. 

Collection  of  the  University  of  Chicago  (No.  6066). 
FIG.  7. — Promo palaeaster  exculptus  (Miller)  (also  see  plate  20). 

Adambulacral  and  ambulacral  plates  at  about  mid-length  of  a  ray,  X  4. 

From  the  holotype. 

Upper  Ordovicic  (Richmondian).    Near  Waynesville,  Ohio. 

Harris  collection  of  the  United  States  National  Museum  (Cat.  No. 
60608). 
FIG.  S.—Promopalssaster  dyeri  (Meek)  (also  see  plates  20  and  25). 

Five  inframarginal  plates  X  4.  To  show  the  articulations  for  the  stout 
spines  that  lie  on  the  right.  Also  note  the  smaller  spines.  The  plate 
extensions  to  the  left  connect  with  the  vertical  ridges  on  the  ambulacral 
plates. 

From  the  holotype. 

Upper  Ordovicic  (Maysvillian).    Cincinnati,  Ohio. 

Dyer  collection  of  the  Museum  of  Comparative  Zoology,  Harvard  Univer- 
sity (No.  13). 

PLATE  19. 

FIG.  1. — Trimeraster  parvulus  Schondorf. 

Reconstruction  X  1.75  of  the  actinal  side.    After  Schondorf. 

Lower  Devonic  (Coblenzian).    Near  Rhens,  Germany. 
FIG.  2. — Promo  palseaster  wykoffi  (Miller  and  Gurley)  (also  see  plate  18). 

Photograph  X  2  of  the  holotype,  showing  the  actinal  side.  One  of 
the  finest  of  Paleozoic  specimens. 

Upper  Ordovicic  (Richmondian).    Near  Madison,  Indiana. 

Collection  of  the  University  of  Chicago  (No.  6066). 


PLATE  20. 

FIG.  1. — Anorthaster  miamiensis  (Miller)  (also  see  plate  13). 

Camera  lucida  drawing  X  5.5  of  one  of  the  interbrachial  areas  of  the 
holotype.  The  only  Paleozoic  form  known  with  the  area  wholly  made 
up  of  adambulacrals. 

Upper  Ordovicic  (Richmondian).    Waynesville,  Ohio. 

Harris  collection  of  the  United  States  National  Museum  (Cat.  No. 
40880). 
FIG.  2.—Promopalseaster  exculptus  (Miller)  (also  see  plate  18). 

Camera  lucida  drawing  X  4  of  an  interbracbial  area.  Note  the  modified 
ambulacral  plates  in  connection  with  the  oral  armature.  Holotype. 

Upper  Ordovicic  (Richmondian).    Near  Waynesville,  Ohio. 

Harris  collection  of  the  United  States  National  Museum  (Cat.  No. 


296  BULLETIN  88,   UNITED   STATES   NATIONAL   MUSEUM. 

FIGS.  3-6. — Promopalseaster  dyeri  (Meek)  (also  see  plates  18  and  25). 

3.  One  of  the  interbrachial  areas  with  the  ossicles  displaced  and  the 
adjoining  adambulacral  plates  with  their  spines,  X  4. 

4.  Madreporite  X  4.    The  rest  of  the  plate  is  covered. 

5.  Two  abactinal  spines,  X  7. 

6.  Five  different  abactinal  ossicles,  X  7. 
All  drawn  from  the  holotype. 

Upper  Ordovicic  (Maysvillian).     Cincinnati,  Ohio. 
Dyer  collection  of  the  Museum  of  Comparative  Zoology,  Harvard  Uni- 
versity (No.  13). 

PLATE  21. 

FIG.  1. — Promopalseaster  magnificus  (Miller)  (also  see  plates  22  and  23). 

Photograph,  natural  size,  of  the  actinal  side  of  one  of  the  cotypes.  This 
speci  nen  is  probably  the  best  preserved  of  Paleozoic  starfishes  and  is  one 
of  the  largest  species. 

Upper  Ordovicic  (Richmondian).    Near  Waynesville,  Ohio. 

Harris  collection  of  the  United  States  National  Museum  (Cat.  No.  40883). 

PLATE  22. 

FIG.  1. — Promopalseaster  magnificus  (Miller)  (also  see  plates  21  and  23). 

Abactinal  side  of  the  same  specimen  illustrated  on  plate  21. 

PLATE  23. 

FIGS.  1-3. — Promopalseaster  magnificus  (Miller)  (also  see  plates  21  and  22). 

1.  Camera  lucida  drawing  X  3.5  of  an  interbrachial  area.    Additional 
tube-feet  probably  also  came  out  at  the  junction  of  the  forked  crests. 

2.  Camera  lucida  drawing  X  4  of  the  actinal  area  of  one  of  the  rays 
toward  the  distal  ends.    Large  adambulacrals  bound  the  rays  distally, 
while  the  smaller  pieces  outside  are  the  inframarginals. 

3.  A  distal  portion  of  the  abactinal  area,  X  3.5. 
All  drawn  from  the  cotypes. 

Upper  Ordovicic  (Richmondian).    Near  Waynesville,  Ohio. 

Harris  collection  of  the  United  States  National  Museum  (Cat.   No. 
40883). 
FIG.  4. — Neopalseaster  crawfordsvillensis  (Miller)  (also  see  plate  13). 

Camera  lucida  drawing  X  4  of  the  abactinal  area  of  the  holotype.  Ac- 
cessory disk  pieces  are  drawn  in;  in  the  specimen  they  are  all  displaced. 
The  madreporite  should  be  more  finely  striate.  In  places  the  dorsal 
skeleton  is  lost,  exposing  the  ambulacrals. 

Mississippic  (Keokuk).    Crawfordsville,  Indiana. 

Harris  collection  of  the  United  States  National  Museum  (Cat.  No. 
60607). 
FIGS.  5-7. — Petraster  spedosus  (Miller  and  Dyer)  (also  see  plates  26  and  27). 

5.  The  ambulacral,  adambulacral  and  inframarginals  of  a  ray  at  its 
mid-length,  X  4.    Seen  from  the  actinal  side. 

6.  Inframarginal,  accessory  interbrachial,  and  adambulacral  pieces,  X  4. 
Seen  from  the  dorsal  side. 

7.  Ambulacral  and  adambulacrale,  X  4.    Seen  from  the  dorsal  area. 


REVISION   OF   PALEOZOIC   STELLEROIDEA.  297 

PLATE  24. 

FIGS.  1-2. — Xenaster  margaritatus  Simonovitsch. 

1.  Reconstruction,    somewhat  enlarged,   of    the   abactinal  side.     The 
structure  of  the  medial  portion  of  the  disk  is  based  upon  Agalmaster 
miellensis. 

2.  Reconstruction,  somewhat  enlarged,  of  the  actinal  area. 
After  Schondorf. 

*    Lower  Devonic   (Upper  Coblenzian).     Niederlahnstein,   Germany. 

PLATE  25. 

FIG.  1. — Promopalssaster  dyeri  (Meek)  (also  see  plates  18  and  20). 

Retouched  photograph,  natural  size,  of  the  actinal  side  of  the  holotype. 

Upper  Ordovicic  (Maysvillian).    Cincinnati,  Ohio. 

Dyer  collection,  Museum  of  Comparative  Zoology,  Harvard  University 
(No.  13). 
FIG.  2. — Lepidasterella  babcocki,  new  species. 

Photograph  X  1.5  of  the  holotype.  A  natural  mold  of  the  abactinal 
area  in  sandstone. 

Upper  Devonic  (Lower  Chemung).     Near  Ithaca,  New  York. 

Collection  of  Mrs.  G.  W.  Babcock. 

PLATE  26. 

FIG.  1. — Petraster  spedosus  (Miller  and  Dyer)  (also  see  plates  23  and  27). 

Retouched  photograph,  natural  size,  of  the  abactinal  area  of  the  holotype. 

Upper  Ordovicic  (Richmondian).   Near  Winchester,  Ohio. 

Dyer  collection  of  the  Museum  of  Comparative  Zoology,  Harvard  Uni- 
versity (No.  14). 
FIG.  2. — Petraster  (?)  americanus  (D'Orbigny). 

Reproduction,  natural  size,  of  Meek's  original  figure.  The  specimen  is 
seen  from  the  abactinal  side,  exposing,  however,  the  inner  surface  of  the 
actinal  skeleton,  which  is  deeply  embedded  in  limestone. 

Upper  Ordovicic  (Maysvillian).   Cincinnati,  Ohio. 

Collection  of  the  University  of  Chicago. 

PLATE  27. 

FIGS.  1-4.— Petraster  spedosus  (Miller  and  Dyer)  (also  see  plates  23  and  26). 

1.  Camera  lucida  drawing  X  4  of  the  abactinal  side  of  a  ray.    Holotype 
The  inframarginals  border  the   animal,  with  the  supramarginals  imme- 
diately inside  of  them.     The  radial  column  is  readily  distinguished 
along  the  center  of  the  rays. 

2.  Camera  lucida  drawing  X  6  of  an  interbrachial  area  in  a  young 
individual  (Harris  collection,  Cat.  No.  60609,  U.S.N.M.).  The  inframar- 
marginals  are  above  and  the  adambulacrals  below  to  the  right.    The  rest 
rest  of  the  plates  are  accessory  interbrachials. 

3-4.  Madreporite  from  the  side  and  from  the  lower  or  under  surface,  X  8. 
FIG.  5. — Petraster  rigidus  (Billings). 

Outline  tracing  of  the  actinal  skeleton  from  a  photograph  X  2  of  the 
holotype. 

Middle  Ordovicic  (Trenton).   Ottawa,  Canada. 
Collection  of  the  Geological  Survey  of  Canada  (No.  1401a). 


298  BULLETIN  88,   UNITED  STATES   NATIONAL   MUSEUM. 

FIGS.  6-8. —  Urasterella  grandis  (Meek)  (also  see  plates  28  and  30). 

6.  Camera  lucida  drawing  X  8  of  part  of  the  abactinal  area  of  a  ray  proxi. 
mally.   Note  how  the  ossicles  are  drawn  out  into  nonarticulating  blunt 
spines. 

7.  Camera  lucida  drawing  X  4  of  the  actinal  side  about  the  mouth.    The 
complete  oral  armature  is  preserved. 

8.  Madreporite  in  outline,  X  7. 

From  specimens  in  the  Harris  collection  of  the  United  States  National 
Museum  (Cat.  No.  40885). 

PLATE  28. 

FIGS.  1  and  2. —  Urasterella  grandis  (Meek)  (also  see  plates  27  and  30). 

1.  Retouched  photograph,  natural  size,  of  a  large  and  folded  specimen. 
Both  ventral  and  dorsal  areas  are  shown. 

2.  Retouched  photograph,  natural  size,  of  an  average  individual  seen 
from  .the  actinal  side. 

Upper  Ordovicic  (Richmondian).    Near  Waynesville,  Ohio. 
Harris  collection  of  the  United  States  National  Museum  (Cat.  No.  40885). 
FIGS.  3  and  4.  —  Urasterella  pulchella  (Billings)  (also  see  plate  30). 

3.  Photograph,  natural  size,  of  an  electrotype,  seen  from  the  actinal  side. 
Middle  Ordovicic  (Trenton).    Hull,  Ottawa,  Canada. 

Original  in  collection  of  the  Geological  Survey  of  Canada;  electrotype  in 
United  States  National  Museum  (Cat.  No.  60610). 

4.  Retouched  photograph,  natural  size,  of  the  abactinal  area. 
Middle  Ordovicic  (Trenton).    Trenton  Falls,  New  York. 

Collection  of  the  Museum  of  Comparative  Zoology,  Harvard  University 
(No.  31). 
FIG.  5.' — Urasterella  girvanensis,  new  species. 

Reproduction  X  2  of  the  original  figure  by  Nicholson  and  Etheridge, 
somewhat  altered. 

From  a  wax  squeeze  made  by  Bather,  now  in  the  United  States  National 
Museum  (Cat.  No.  60611). 

Upper  Ordovicic.    Thraive,  Girvan,  Scotland. 

PLATE  29. 

FIG.  1. —  Urasterella  ulrichi,  new  species  (also  see  plate  30). 

Retouched  photograph,  natural  size,  of  the  abactinal  side  of  a  cotype. 
The  three  short  blunt  rays  are  interpreted  as  healed  stumps. 

Middle  Ordovicic  (Black  River).    Minneapolis,  Minnesota. 

Ulrich  collection  of  the  United  States  National  Museum  (Cat.  No.  60612). 
FIG.  2.  —  Urasterella  huxleyi  (Billings). 

Photograph  X  2  of  the  holotype.    Abactinal  view. 

Middle  Ordovicic  (about  Chazy).    Point  Rich,  Newfoundland. . 

Collection  of  the  Geological  Survey  of  Canada  (No.  554.) 

PLATE  30. 

FIGS.  1-4. —  Urasterella  grandis  (Meek)  (also  see  plates  27  and  28.) 

1-2.  Camera  lucida  drawing  X  16  of  the  adambulacrals  with  their  articu- 
lar spines  and  probable  paxillse. 

3.  Camera  lucida  drawing   X   8  of   the  two  columns  of  ambulacra! 
plates   a  little   displaced.    The   podial   openings   are  situated   laterally 
between  the  thinner  ends  of  the  ossicles. 

4.  Camera  lucida  drawing  X  7  of  the  adambulacrals  with  their  spines. 
From  specimens  in  the  Harris  collection  of  the  United  States  National 


REVISION   OF   PALEOZOIC    STELLEROIDEA.  299 

FIG.  5. —  Urasterella  pulchella  (Billings)  (also  see  plate  28). 

Camera  lucida  drawing  X  8.  The  large  plates  to  the  left  are  the  coin- 
shaped  adambulacrals  (some  have  tipped  over  and  show  their  articular 
faces),  next  are  the  small  elongate  inframarginals,  and  outside  of  these 
are  the  spinose  ambitals. 

FIGS.  6  and  7. —  Urasterella  ulrichi,  new  species  (also  see  plate  29). 

6.  Camera  lucida  drawing    X   4  of  the  abactinal  side  of  a   young 
individual.    The  medial  ray  plates  should  be  more  tumid  than  here 
represented.     Note  the  primitive  structure  of  the  disk. 

7.  Camera  lucida  drawing  X  6  of  the  actinal  side  of  a  young  indi- 
vidual.   The  outer  dark  margin  is  adhering  rock,  through  which  some 
of   the   abactinal   ambital    nonarticulating   spines   project.    Note   the 
phanerozonian  interbrachial  characters. 

Middle  Ordovicic  (Black  River).    Minneapolis,  Minnesota. 
Ulrich  collection  of   the    United    States   National    Museum   (Cat 
No.  60612). 

PLATE  31. 

FIGS.  1  and  2. — Compsaster  formosus  Worthen  and  Miller. 

1.  Actinal  view,  natural  size,  of  the  holotype.     Reproduction  of  the 
original  illustration. 

2.  Part  of  a  ray,  X  2.   After  Worthen  and  Miller. 
Upper  Mississippic  (Chester).   Okaw  Bluffs,  Illinois. 
"  Illinois  State  collection  of  1880,  No.  2476." 

FIG.  S.—Calliasterella  mira  (Trautschold). 

Reproduction,  natural  size,  of  Schondorf's  reconstruction. 

Upper  Carboniferous  (Moscovian).   Mjatschkowa,  near  Moscow,  Russia. 

PLATE  32. 
FIG.  1. — Stenaster  salteri  Billings. 

Retouched  photograph  X  3  of  a  cotype.   Actinal  view. 

Middle  Ordovicic  (Trenton).   Belleville,  Ontario,  Canada. 

Collection  of  the  Geological  Survey  of  Canada. 
FIG.  2. — Schuchertia  stellata  (Billings)  (also  see  plate  33). 

Photograph  X  4  of  the  actinal  side  of  the  holotype. 

Middle  Ordovicic  (Trenton).    Ottawa,  Canada. 

Collection  of  the  Geological  Survey  of  Canada  (No.  1399). 
FIG.  3. — Schuchertia  laxata,  new  species  (also  see  plate  33). 

Retouched  photograph  X  2  of  the  holotype  from  the  abactinal  side. 

Upper  Ordovicic  (Richmondian).  Waynesville,  Ohio. 

Harris  collection  of  the  United  States  National  Museum  (Cat.  No.  60613). 
FIGS.  4  and  6. — Schcenaster  (?)  legrandensis  Miller  and  Gurley. 

4-5.  Actinal  and  abactinal  views,  natural  size. 

6.  Part  of  actinal  side  X  6.5.    After  Miller  and  Gurley. 

Lower  Mississippic  (Kinderhookian).   Le  Grand,  Iowa. 

?Gurley  collection  of  the  University  of  Chicago. 

PLATE  33. 

FIG.  1. — Schuchertia  stellata  (Billings)  (also  see  plate  32). 

Camera  lucida   drawing    X    8   of  the   abactinal  surface.    Somewhat 
restored. 

Middle  Ordovicic  (Trenton).     Near  New  Edinburgh,  Canada. 

Collection  of  the  Geological  Survey  of  Canada. 
FIGS.  2  and  3. — Schuchertia  laxata,  new  species  (also  see  plate  32). 

2.  Some  of  the  outer  ambital  plates,  all  disjointed,  X  8. 

3.  An  interbrachial  area  and  ambulacrum,  X  4. 
Upper  Ordovicic  (Richmondian).    Waynesville,  Ohio. 

Harris  collection  of  the  United  States  National  Museum  (Cat.   No. 


300  BULLETIN  88,   UNITED  STATES   NATIONAL   MUSEUM. 

FIG.  4. — Tetraster  wyville-thoTtisoni  Nicholson  and  Etheridge. 

Diagram  X  4  of  the  actinal  skeleton.    From  a  wax  squeeze  by  Bather, 
in  the  United  States  National  Museum  (Cat.  No.  60614). 

Upper  Ordovicic.    Thraive,  Girvan,  Scotland. 
FIG.  5. — Schcenaster  (?)  montanus  Raymond. 

Reproduction  X  2  of  the  original  figure.    Actinal  side. 
Mississippi  (Madison).    Spring  Canyon,  near  Alder,  Montana. 
Collection  of  the  Carnegie  Museum. 
FIG.  6. — SJicenaster  (?)  wachsmuihi  Meek  and  Worthen. 

Reproduction,  natural  size,  of  the  original  figure.    Actinal  view. 
Lower  Mississippi  (Burlington).    Burlington,  Iowa. 
Collection  of  the  Museum  of  Comparative  Zoology,  Harvard  University 
(No.  7). 

PLATE  34. 

FIG.  1. — Palseosolaster  (?)  gyalum  (Clarke). 

Actinal  view  of  one  of  the  cotypes,  natural  size. 
Upper  Devonic  (Portage).  Ithaca,  New  York. 
Collection  of  Cornell  University. 

PLATE  35. 

FIGS.  1-4. — Schcenaster  fimbriatus  Meek  and  Worthen. 

1.  View  of  the  abactinal  side,  natural  size,  of  one  of  the  cotypes. 

2.  Enlarged  view  of  one  of  the  rays,  showing  the  arrangement  of  the 
ossicles  and  the  pores,  as  seen  when  the  surface  is  ground  down. 

3.  Actinal  side  of  a  ray,  enlarged,  showing  only  the  adambulacrals. 

4.  Actinal  side  of  another  cotype,  natural  size. 
The  original  figures  of  plate  19,  figs.  7 a  to  7d. 

Upper  Mississippi  (St.  Louis).    St.  Clair  County,  Illinois. 
FIGS.  5  and  6 — Encrinaster  petaloides  (Simonovitsch). 

5.  Abactinal  view,  about  X  2. 

6.  An  arm  from  the  actinal  side,  about  X  2. 
After  Schondorf. 

Lower  Devonic  (Upper  Coblenzian).     Niederlahnstein,  Germany. 

PLATE  36. 

FIG.  1. — Tseniaster  spinosus  (Billings). 

Photograph  X  2  showing  the  actinal  side  of  one  of  the  cotypes. 
Middle    Ordovicic    (Lower    Trenton).     Montmorency    Falls,    Quebec, 
Canada. 

Collection  of  the  Geological  Survey  of  Canada  (No.  1404). 
FIGS.  2  and  3.—Taeniaster  cylindricus  (Billings). 

2.  Abactinal  view  X  2  of  one  of  the  cotypes. 

3.  Actinal  view  X  2  of  another  cotype.     Both  specimens  are  on  the 
same  slab. 

Middle  Ordovicic  (Trenton).     Ottawa,  Canada. 
Collection  of  the  Geological  Survey  of  Canada  (No.  1405a). 
FIG.  4. — Alepidaster  flexuosus  (Miller  and  Dyer). 

An  unpublished  photograph  X  3.5,  made  many  years  ago,  of  the  holo- 
type  of  Protasterina  fimbriata  Ulrich. 

Upper  Ordovicic  (Lower  Edenian).    Covington,  Kentucky. 
Ulrich  collection  of  the  United  States  National  Museum  (Cat.  No.  60615). 


REVISION   OF   PALEOZOIC   STELLEKOIDEA.  301 

PLATE  37. 

FIGS.  1  and  2. — Eucladia  woodwardi  Sollas. 

Dorsal  and  ventral  reconstructions  X  5/3  of  this  remarkable  fossil.    On  it 
is  based  the  order  Ophiocistia  Sollas.     "One  arm,  the  most  proximal  of 
the  radius  on  the  lower  right-hand  corner,  is  omitted,  so  as  to  show  the 
aperture  from  which  it  proceeds."    After  Sollas. 
Siluric  (Lower  Ludlow).     Leintwardine,  England. 

PLATE  38. 

FIG.  l.—Eucladm  (?)  beecheri,  new  species. 

Photograph  X  2  of  the  holotype  from  the  actinal  side.  The  specimen 
itself  is  difficult  to  make  out,  hence  the  indistinctness  of  the  photograph. 

Lower  Devonic  (Coeymans).  Jerusalem  Hill,  Litchfield,  Herkimer 
County,  New  York. 

Collection  of  Peabody  Museum,  Yale  University. 


U.   S.    NATIONAL   MUSEUM 


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HUDSON  ASTER   NARRAWAYI. 

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1,    HUDSONASTER  NARRAWAYI;  2,    H.   MATUTINUS. 

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1,   HUDSONASTER  RUGOSUS;  2,    H.   MATUTINUS;  3,   H.   BATHERI. 

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1,    HUDSONASTER  NARRAWAYI;  2,    H.   MILLERI;    3,    MESOPAL/EASTER  (?)   LANCEOLATUS; 
4,  AUSTRALASTER  GIQANTEUS. 

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HUDSONASTER   MATUTINUS. 

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HUDSONASTER   INCOMPTUS. 

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1-4,  PAL/EASTER  NIAGARENSIS;  5,  MESOPAL/EASTER  FINEI 

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1,  2,  MESOPAL/EASTER  SHAFFERI;  3,  MIOMASTER  DREVERMANNI. 

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Six  SPECIES  OF  MESOPALXE ASTER. 

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MESOPAL/E  ASTER  CLARKI. 

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,  MESOPAL/EASTER  CARACTACI;  2,  DEVONASTER  CHEMUNGENSIS. 

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1 ,  2,  SPANIASTER  LATISCUTATUS;  3-5,  DEVONASTER  EUCHARIS. 

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1-3,  PROMOPAMEASTER;  4,  ANORTHASTER;  5,  NEOPAL/EASTER. 

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Asterlas     prtmorci  tails 


PROMOPALXEASTER  SPECIOSUS. 

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1-4,  PROMOPAL/EASTER  SPECIOSUS;  5,  P.  PRENUNTIUS;  6-8,  P.  BELLULUS. 

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1,  PROMOPAL/EASTER  BELLULUS;  2,  P.  SPINULOSUS. 

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PROMOPAL/CASTER  SPINULOSUS. 

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4 


DETAIL  OF  FIVE  SPECIES  OF  PROMOPAL/EASTER. 

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1 ,  TRIMERASTER  PARVULUS;  2,  PROMOPAL/EASTER  WYKOFFI. 

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1,  DETAIL  OF  ANORTHASTER;  2-6,  PROMOPAL/EASTER. 

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PROMOPALXEASTER  MAGNIFICUS. 
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PROMOPAL/EASTER  MAQNIFICUS. 

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1-3,  DETAIL  OF  PROMOPALXEASTER;  4,  NEOPAL/EASTER;  5-7,  PETRASTER. 

• 

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XENASTER  MARQARITATUS. 

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1,  PROMOPAL/EASTER  DYERI;  2,  LEPIDASTERELLA  BABCOCKI. 

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i 


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wtt. 

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1,  PETRASTER  SPECIOSUS;  2,  P.  (?)  AMERICANUS. 


U.  S.   NATIONAL  MUSEUM 


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1-5,  DETAIL  OF  PETRASTER;  6-8,  URASTERELLA. 

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1,  2,  URASTERELLA  GRANDIS;  3,  4,  U.  PULCHELLA;  5,  U.  QIRVANENSIS. 

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1,  URASTERELLA  ULRICHI;  2,  U.  HUXLEYI. 

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DETAIL  OF  URASTERELLA. 

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1,   COMPSASTER   FORMOSUS;  2,   CALLIASTERELLA   MIRA. 

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1,  STENASTER;  2,   3,  SCHUCHERTIA;  4-6,   SCHCENASTER  (?). 


U.  S.   NATIONAL  MUSEUM 


BULLETIN  88     PL.  33 


^K^fflK^ 


1-3,  DETAIL  OF  SCHUCHERTIA;  4,  TETRASTER;  5,  6,  SCHCENASTER  (?). 


U.  S.   NATIONAL  MUSEUM 


BULLETIN  88     PL.  34 


.~~ 


Kg^K,         ji   ^  .^ 

"•^l^te'^ 


PAL/EOSOLASTER  (?)  GYALUM. 

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1-4,   SCHCENASTER   FIMBRIATUS;  5,  6,    ENCRINASTER   PETALOIDES. 

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1,  T>ENIASTER  SPINOSUS;  2,   3,  T.  CYLINDRICUS;  4,  ALEPIDASTER  FLEXUOSUS. 

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EUCLADIA  WOODWARDI. 

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EUCLADIA  (?)   BEECHERI. 

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INDEX. 


[The  important  references  In  each  case  are  in  heavy-faced  type.    Synonyms  are  in  italics.] 


Page. 

abactinal 13 

abnormal  development 101 

aboral,  see  abactinal. 

accessory  actinals 13 

accessory  interbrachials 13, 15,45,46 

accessory  plates 13,  47, 51 

Acroura  ( Ophiura)  schlotheimii 18 

actinal 13 

acuminatus,  Asterias. ., 93 

acuminatus,  Mesopalseaster  (?) 75, 93 

acuminatus,  Roemeraster  (?) 93 

adambulacralia,  see  adambnlacrals. 

adambulacral  oral  skeleton 16 

adambulacral  spines 13, 43 

adambulacrals  (see  also  lateral  shields) 13, 

34,43,162,213,214,222 

Agalmaster 40, 49, 128, 13 1 , 133 

A.grandis 132 

A.  intermedium 133 

A.miellensis 132 

Aganaster 263 

A .  gregarius 264 

A.  (?)  sp.  Miller  and  Gurley 251 

Aganasteridse 246, 263 

Alepidaster 216,228 

A.  flexuosus 230, 231 

A.  granuliferus 229, 230 

A.  gregarius 264 

A.  miamiensis '. 230, 238 

A.  n.  sp 230 

ambital  and  ambital  plates 13, 46, 174 

ambulacralia,  see  ambulacrals. 

ambulacral  oral  skeleton 16 

ambulacrals 13,33,34,41,213,235,258 

alternate  arrangement 13, 

33, 41 , 152, 172, 174, 213, 214, 215, 222, 226 

opposite  arrangement 13, 

41,163,213,214,224,246 

americanus,  Cadaster 146 

americanus,  Petraster  (?) 139, 146 

ampullae 213 

anal  opening 13,89,54,61 

Anorthaster 41,42,43,50, 125 

A.  miamiensis 127 

Anorthasterinse 52, 74, 126 

anthonii,  A  sterlas 146 

antiqua,  Argaster 86 

antiqua,  Asterias,  Hisinger 149 

antiqua,  Asterias,  Troost 86 

antiqua,  Hisingeraster 149 

antiqua,  Palseaster  (Argaster) 80 

antiqua,  Palxasterina 149 

50601°— Bull.  88—15 20 


Page. 

antiqua,  Palmipes 149 

antiqua,  Petraster  (?) 86 

antiquata,  Asterias 109 

antiquata,  Palxaster 109 

antiquus,  Asteriscus 149 

antiquus,  Lindstromaster 149, 153 

antiquus,  Mesopalseaster  (?) 75, 86 

antiquus,  Palxaster 86 

anus,  see  anal  opening. 

approximata,  Palxasterina 142 

A  rchxasterias 129, 130 

arcs,  see  axil. 

? Argaster 74, 77, 87 

A .  antiqua 86 

arnoldi,  Aspidosoma 243 

arnoldi,  Encrinaster 241, 248 

asper,  Onychaster 270, 2  72 

asperrima,  Palxaster. 187 

asperrima,  Urasterella  (?) 175, 18 7 

asperrimus,  Salteraster 187 

asperrimus,  Tetraster 187 

asperula,  A  sterias 188, 262 

asperula,  Roemeraster 188 

asperula,  Urasterella 175, 188 

Aspidosoma 241 

A .  arnoldi 243 

A.eifelense 244 

A.  goldfussi 243 

A .  gray  se 245 

A.  petaloides 243 

A.  petaloides  goslariensis 243 

A .  ?  pontis 244 

A .  roemeri 244 

A.  sehmidti 244 

A.  tischbeinianum 244 

Aspidosomatidx 241 

Asterias 33 

A  sterias  Graham,  Anthony  and  James 146 

A .  acuminatus 93 

A .  anthonii 146 

A .  antiqua  Hisinger. 149 

A .  antiqua  Troost 86 

A .  antiquata 109 

A,  asperula 188,262 

A.constellata 187 

A.  matutina 57 

A.  montanus 189 

A .  primxva 167 

A .  primordialis 108 

A.  (Archxasterias)  rhenana 131 

A.  spinosissima 19 

asterid  radicle 34 

ysterina 33 

303 


304 


INDEX. 


Page. 

Asteriscus  antiquut 149 

Asteroidea 41, 42, 43, 51 

evolution  of 11, 30, 48, 52, 106 

number  of,  in  Paleozoic 2 7, 28 

terminology 13 

Astropecten 161 

A.  (?)  schliiteri 161 

Ataxaster 161 

A.  pygmseus 161 

Auluroidea 80,38,40,41,42,43,163,212,213 

geological  distribution  of 28 

number  of,  in  Paleozoic 27,28 

Australaster 44,45,49,66,72,  171 

A.giganteus 73,  171 

A.  (?)  stutchburii 73 

australis,  Txniaster 236 

axil 14 

axillary  inframarginal 14 

axillary  interbrachial 14 

axillary  marginal 15 

axillary  ossicles 34, 49 

babcocki,  Lepidasterella 160 

barrisi,  Onychaster 270, 272 

barrisi,  Protester  (?) 272 

bathed,  Hudsonaster J 55, 65,  167 

Bdellacoma 248,252,254 

B.  vermiformis 254 

beecheri,  Eucladia  (?) 278 

bellulus,  Mesopalseaster 75, 91 

bellulus,  Petraster 91 

bellulus,  Promopalseaster 104, 105, 1 13 

beneckei,  Bundenbachia 234 

bibliography 281-288 

biforis,  Protaster 226,  227 

bivium 14 

body-wall 14 

bohemica,  Eophiura 222 

Bohemura 216, 22 8 

B.jahni 223 

bonneyi,  Palxasterina 153 

bonneyi,  Palasterina 151, 152, 168 

brisingoides,  Protaster 236 

brisingoides,  Stiirtzura 236 

buccal  processes 225 

Bundenbach 29 

Bundenbachia 216, 284 

B .  beneckei 234 

B.  grandis 235 

caecal  pores 14 

Calliaster 190 

C.  mirus 190 

Calliasterella 39, 47, 49,50, 190 

C.  mira 191 

Calliasterellidse 162, 163, 190 

Calliasteridx 190 

caractaci,  Mesopalseaster 75, 92 

caractaci,  Palseaster 92 

caractaci,  Protopalxaster 92 

carbonarius,  Cribellites 274 

carinals,  see  radials. 

catalogue  of  Paleozoic  Stelleroidea 51 

cataractensis,  Mesopalaeaster  (?) 75, 89 

central  disk,  see  disk. 

central  disk  plate,  see  centrodorsal  plate. 

central  plate,  see  centrodorsal  plate. 

centrodorsal  plate 14, 34,35,48 


Page. 

Cheiropteraster 40, 199, 202,  252 

C.  giganteus 202 

chemungensis,  Devonaster 101 

Cholaster 265 

C.  peculiaris 266 

Cholasteridse 246, 265 

ciliaris,  Ophiura 268 

clarkana,  Palseaster 61,63 

clarkei,  Etheridgaster 172 

clarkei,  Monaster 171, 1 7  2 

clarkei,  Palseaster,  De  Koninck 172 

clarkei,  Palseaster,  Miller 61 

clarki,  Mesopalaeaster  (?) 75, 94 

clarki,  Palxaster 94 

Classification 51 

Cadaster 95 

C.  americanus 146 

C.  latiscutatus 96 

C.  tenuiradiatus 19 

colvini,  Palzocoma 253 

colvini,  Stiirtzaster 253 

Compsaster 192 

C.  formosus 193 

C.  n.sp 194 

Compsasteridse 162, 163, 191 

concinna,  Eugasterella  (?) 238, 289 

concinnus,  Eugaster 239 

confluens,  Stenaster  (?) 165,167 

confragosus,  Onychaster 270, 273 

constellata,  Asterias 187 

constellata,  Urasterella  (?) 175, 187 

coronella,  Palxaster 167 

coronella,  Stenaster  (?) 165, 167 

crawfordsvillensis,  Neopalseaster 135, 186 

crawfordsvillensis,  Palaeaster 136 

Cribellites  carbonarius 274 

Crossaster 38 

Cryptozonia....  80,33,38,40,41,43,44,45,46,47,162 

cygnipes,  Palseocoma 253 

cygnipes,  Sturtzaster. 253 

cylindrica,  Lapworthura 220 

cylindrica,  Palseocoma 220 

cylindrica,  Txniura. 220 

cylindricus,  Tseniaster 216,217,218,219,220 

daoulasensis,  Furcaster  (?) 261 

daoulasensis ,  Protaster 261 

darwini,  Echinasterella  (?) 200 

decheni,  Eoluidia 262 

decheni,  Eophiurites 262 

decheni,  Protaster 248 

decheni,  Tremataster  (?) 247, 248 

demissus,  Onychaster 270,274 

development,  abnormal 101 

geological,  of  Stelleroidea 27, 28 

Devonaster 40, 44, 

46, 47, 49, 50, 74 , 76, 77, 9  7 , 129, 130, 133 

D.  chemungensis 101 

D.eucharis 29,37,98 

devonica,  Palxnectria 155 

devonicus,  Palasteriscus 200 

difflcilis,  Tremataster 247 

disk 14,213,225 

how  enlarged 32 

disk  accessory  plates 34, 46 

disk  ambitals 13 

disk  inframarginals 15 


INDEX. 


305 


disk  marginals 14 

disk  plates 14 

primary 49,179,184,190,191 

disk  supramarginals 15 

dispar,  Xenaster 130, 131 

dorsal,  see  abactinal. 
dorsals,  see  radials. 

dorsal  shield 213 

dorso-laterals,  see  accessory  plates. 

drevermanni,  Miomaster 96 

dubius,  Mesopalseaster  (?) 75, 85 

dubius,  Palxaster 85 

dyeri,  Palxaster 120 

dyeri,  Petraster 121 

dyeri,  Promopalaeaster 104, 105, 120 

Echinaster 45 

Echinasterella 199, 200 

E.  (?)  darwini 200 

E .  sladeni 200 

EcMnasterias 38,207,209, 211 

E.  spinosus 211 

echinatus,  Squamaster 249 

Echini,  radii  of 35 

Echinodiscaster 38,40,207,209,211 

E.  multidactylus 211 

Echinodiscites 211 

Echinodiscus 211 

E.  multidactylus 211 

Echinostella 38,207,209,212 

E.  traquairi 212 

Eifelaster 128, 133 

E.  follmanni 134 

eifelense,  Aspidosoma 244 

eifelensis,  Encrinaster 244 

elegans,  Protaster 221 

elegans,  Tseniaster 219,221 

elegans,  Xenaster 130, 131 

elizae,  Uranaster 155 

Encrinaster  (part) 224 

Encrinaster 43, 45, 226, 241 

E.  arnoldi....; 241,243 

E.  eifelensis 244 

E.goldfussi 243 

E.  (?)grayae 245 

E.petaloides 243 

E.  petaloides  goslariensis 243 

E.pontis 244 

E.  roemeri 242, 244 

E.  schmidti 244 

E.  tischbeinianus 244 

Encrinasterix  (part) 215 

Encrinasteridse 215, 241 

Eoactis 173,178 

E.  simplex 186 

Eoluidia 262 

E.  decheni 262 

Eoluidiidse 246,262 

Eophiura 216,222,223,259 

E .  bohemica 222 

Eophiuridx 262 

Eophiurites 262 

E.  decheni 262 

Eospondylus 262, 2  63 

E .  primigenius 263 

Etheridgaster 170 


Page. 
E.  clarkei 172 

eucharis,  Devonaster 29,37, 98 

eucharis,  Palxaster 93 

eucharis,  Xenaster 93 

Eucladia 275, 276 

E.  (?)beecheri 278 

E.  johnsoni 276 

E.  woodwardi 276, 277 

Eucladiidge 276 

Eugaster 237 

E.  concinnus 239 

E.  logani 238 

Eugasterella 235, 237,  259 

E.  (?)  concinna 238, 239 

E .  logani 237, 2  3  8 

Euophiuroidea 213 

EuryalQ  annulatum 20 

Euthemon.....' 275,276, 279 

E.  igerna 279 

evolution  of  Asteroidea .% 30 

exculptus,  Palxaster 117 

exculptus,  Promopalseaster 104, 105, 117 

eye-plate,  see  ocular  plate. 

ferox,  Palaeodiscus 23 

filiciformis,  Helianthaster 159, 1 60 

fimbriata,  Palxasterina 204 

fimbriaid,  Protaster 231 

fimbriata,  Protasterina 231 

fimbriatus,  Schoenaster 204 

flnei,  Mesopalseaster 75, 81 

fine  i  Palxaster 81 

flexilis,  Onychaster 269, 270 

flexuosus,  Alepidaster 230, 231 

flexuosus,  Protaster 231 

flexuosa,  Protasterina 231 

follmanni,  Eifelaster 134 

follmanni,  Palasterina 157 

follmanni,  Pseudopalasterina 156, 157 

forbesi,  Hallaster 254, 2 66 

forbesi,  Protaster 255 

formosus,  Compsaster 193 

Furcaster 248,259, 261 

F.  (?)  daoulasensis 261 

F.  palseozoicus 259, 261 

Furcasteridx 248 

genitals,  see  interradial  plates. 

genitals  in  Echini 35 

geological  development  of  Stelleroidea 27, 28 

geological  distribution  of  Stelleroidea 28 

giganteus,  Australaster 73, 171 

giganteus,  Cheiropteraster 202 

giganteus,  Monaster 73 

giganteus,  Palxaster  ( Monaster) 73 

girvanensis,  Urasterella 167, 175, 186 

goldfussi,  Aspidosoma 243 

goldfussi,  Encrinaster 243 

Goniaster 61 

grandis,  Agalmaster 132 

grandis,  Sundenbachia 235 

grandis,  Palseophiomyxa 234, 286 

grandis,  Stenaster 180 

grandis,  Urasterella 174, 175, 180 

granti,  Mesopalaeaster 75, 89 

granti,  Palxaster 89 

granuliferus,  Alepidaster 229, 280 


306 


INDEX. 


Page. 

granuliferus,  Protester  (f) 230 

granulosus,  Palxaster,  Hall 112 

granulosus,  Palxaster,  Meek 109 

granulosus,  Promopalaeaster 104, 1 1 2, 113 

graspers 33 

grayx,  Aspidosoma 245 

grayse,  Encrinaster  (?) 245 

grayi,  Lepidast*r 158 

gregarius,  Aganaster 264 

gregarius,  Alepidaster 264 

gregarius,  Protester  (/) 264 

Gregoriura 216,233 

G.  spryi 234 

gregoryi,  Palseosolaster 209 

groomi,  Protaster 226, 227 

gyalum,  Helianthaster 160,210 

gyalum,  Palseosolaster  (?) 210 

Hallaster 248, 254 

H.  forbesi 254, 255 

Harris,  I.  H.,  gift  oietarflshes  by 9 

Jiarrisi,  Palxaster 180 

Helianthaster  Clarke  (part) 209 

Helianthaster  Roemer 38, 

40,45,157,158,159,209,211 

H.  flliciformis 159,160 

H.  gyalum  (part) 160, 210 

H.  rhenanus 159 

H.roemeri 209,211 

H.  n.  sp .  Clarke 160 

Helianthasteridx 157 

Helianthasterinse 157 

Heliaster 38,208 

hirudo,  Palxaster 188 

Urudo,  Uraster 188 

hirudo,  Urasterella 175,188 

Hisingeraster 148 

H,  antiqua 149 

Hudsonaster 31,32,34,36, 

38, 39, 40, 41, 42, 44,45, 47, 48,  49, 52, 68, 
69, 75, 105, 135, 140, 158, 165, 179, 194, 196 

H.batheri 55,65,167 

H.  incomptus. 34,36,40,55,61 

H.  matutinus 34,55, 57, 139, 141, 166 

H.  milleri .....  55,60 

H.narrawayi 43,50,55,59 

H.  rugosus 36, 55, 64 

Hudsonasteridse] 52, 53,162 

huxleyi,  Stenaster 182 

huxleyi,  Urasterella 175, 182 

igerna,  Euthemon 279 

imbricatus,  Palxaster 169 

imbricatus,  Tetraster  (?) 168, 169 

incomptus,  Hudsonaster 34,36,40,55, 61 

incomptus,  Palxaster. 61 

inframarginalia 16, 34, 48, 152, 194 

inframarginal  plates 16, 33, 174, 179, 185 

Interact]  nals 13 

interbrachial  adambulacrals 1 5, 126 

interbrachial  areas  and  arcs.. . .  14,  60, 138, 185, 194 

interbrachial  marginals 15 

intennarginal  plates,  see  ambital  plates, 
intermarginals,  see  ambital. 

intermedius,  Agalmaster 133 

intermedius,  Mesopalseaster 75, 79 

interadial  plates 15, 32 

Jaekelaster 40, 192 


Page. 

J.  petaliformis 192 

jahni,  Bohemura 223 

jamesi,  Palxaster 146 

jamesi,  Palasterina  (t) 146 

johnsoni,  Eucladia 276 

kinahani,  Palasterina 155 

kinahani,  Uranaster 154, 155 

Labidaster 208 

lanceolatus,  Mesopalaeaster  (?) 75, 82 

Lapworhtura 248, 250, 254 

L.  cylindrica 220 

L.  miltonl 250,261,253 

L.  sollasi. 251 

L.  (?)sp 251 

Lapworthuridae 246, 248 

lateral  shields 214 

latiscutetus,  Coelaster 96 

latiscutatus,  Spaniaster 96 

laxata,  Schuchertia 196, 198 

legrandensis,  Schoenaster  (?) 206 

Lepidaster 38,40,158,160 

L .  grayi 158 

Lepidasteracea 53 

Lepidasterella 38, 40, 1 60 

L.babcocki 160 

Lepidasteridae 52,53,157 

leptosoma,  Protaster 237 

leptosoma,  Rhodostoma 237 

leptosoma,  Sturtzura 236, 237 

leptosomoides,  Sturtzura 236, 237 

Lindstromaster 138, 140, 148, 154, 156 

L.  antiquus 1 4  9 , 153 

Lindstromasterinx 138 

logani,  Eugaster 238 

logani,  Eugasterella 237, 288 

longibrachiatus,  Palxaster 115 

Loriolaster 199,200, 201, 202,252 

L.  mirabilis 201 

lymani,  Ophiurina 247 

Lysophiurae 215 

madreporite 15,39,40,209,211,214,222,223,226 

magniflcus,  Promopalaeaster 42, 

104,105,106,113,122 

margaritetus,  Xenaster 131,132 

margaritatus,  Xenaster 129, 130, 181 

marginalia,  see  marginal  plates. 

marginal  plates 1 6,33, 43, 135, 152, 213 

marstoni,  Palxocoma 253 

marstoni,  Sturtzaster 253 

matutina,  Asterias 57 

matutinus,  Hudsonaster 34, 55, 6 7,139, 141, 166 

matutinus,  Palxaster 67 

meafordensis,  Tseniaster 221 

measurements 15 

median  dorsals,  see  radials. 

Medusaster 38,207,212 

M.  rhenanus 212 

Mesopaleeaster 28, 39, 41, 44, 45, 46, 47, 49, 

50, 56,  74,95,98, 105, 126, 130, 135, 158 

M.(?)  acuminatus 75, 93 

M.  (? )  antiquus 75, 8  6 

M.beUulus 75,91 

M.  caractaci 75, 92 

M.(?) cataractensis 75,89 

M.(?)clarki 75,94 

M.(?)dubius 75,85 


INDEX. 


307 


Page. 

M.finei 75,81 

M.  grant! 75,89 

M.  intermedius 75, 79 

M.(?)  lanceolatus 75, 82 

M.(?)  parviusculus 75, 87 

M.  proavitus 75, 83,85 

M.shafferi 44,75,77 

M.(?)  wilberanus 75, 84 

Mesopalseasterinae 52, 74,162 

miamiensis,  Alepidaster 230, 238 

miamiensis,  Anorthaster 127 

miamiensis,  Palseaster 127 

miamiensis,  Protaster 233 

miellensis,  Agalmaster 132 

milleri,  Hudsonaster 55, 60 

miltoni,  Lapworthura 250, 251, 253 

mittoni,  Protaster 251 

minveri,  Sympterura. . : 256 

Miomaster 43,50, 74, 96 

M.  drevermanni 96 

Miospondylus 262, 263 

M.  rhenanus 263 

mira,  Calliasterella 191 

mirabilis,  Loriolaster 201 

mirus,  Calliaster 190 

mitchelli,  Sturtzaster  (?) 254 

Monaster  Gregory 49, 72 

Monaster  Etheridge 40, 1 70 

M.  Clarkei 171, 172 

M.  giganteus 73 

M .  stutchburii 73 

Monasteridae 162, 163, 1 70 

montana,  Urasterella 175, 189 

montanus,  Asterias 189 

montanus,  Palseaster 189 

montanus,  Schoenaster  (?) 43, 207 

mouth  angle  plate,  see  oral  armature. 

multidactylus,  Echlnodiscaster 211 

multidactylus,  Echinodiscus 211 

multlrayed  starfishes 38, 40, 157, 207 

narrawayl,  Hudsonaster 43, 50, 55, 69 

narrawayi,  Protopalseaster 59 

neglecta,  Palseura 223 

Neopalseaster 40, 43, 48, 49, 57, 69, 98, 134 

N.  crawfordsvillensis 135, 136 

Neopalseasteridse 52,53, 184 

niagarensis,  Palaeaster 68, 69 

obtusus,  Ophiura 25 

obtusus,  Palssaster 167 

obtusus,  Protaster  (Ophiura) 25 

obtusus,  Stenaster  (?) 165, 167 

obtusus,  Uraster 167 

occurrence  of  starfishes 28 

ocularplate 16,34,48,134,135 

oculars  in  Echini 35 

ontogeny  of  Stelleroidea 36 

Onychaster 268 

O.asper 270,272 

O. barrisi 270, 272 

O.  confragosus 270, 273 

O.  demissus 270, 274 

O.flexllis 269,270 

Onychasteridse 268 

Ophiocistia 275 

Ophio-Encrinasterix .' 215 

OpJiiopege 263 


Page. 

Ophiura  ciliaris 268 

O.  obtusus 25 

O.  (?)ramosa 22 

O .  rhenana 263 

O .  salteri 227 

O.  schlotheimii 13 

Ophiurasterix 215,246 

Ophiurella 263 

0-  primigenia 263 

Ophiurina 246, 260 

O.  lymani 247 

Ophiurinidse 246 

Ophiuroidea 41, 42, 43, 2 1 2 , 258, 267 

geological  distribution  of 28 

number  of,  in  Paleozoic 27, 28 

oral,  see  actinal. 

oral  angles 16 

oral  armature 16, 43, 162, 172, 210, 242 

oral  skeleton,  see  oral  armature. 

ordinaria,  Schuchertia 196, 199 

ossicles,  see  plates. 

Palseaster 10, 

40, 41, 44, 49, 56, 66, 67 ,  75, 98, 104, 135, 158 

Palseaster  (Monaster)  Etheridge  (part) 72,170 

P.  (Argaster)  antiqua 86 

P.  antiquata 109 

P.  aniiquus 86 

P.  asperrima 187 

P.  caractad 92 

P.  clarkana 61,63 

P.  clarke i  De  Koninck .- 172 

P.  clarkei  Miller 61 

P.darki : 94 

P.  coronella 167 

P.  crawfordsvillensis 136 

P.dubius 85 

P.dyeri 120 

P.  eucharis 98 

P.exculptus 117 

P.  fin* 81 

P.  (Monaster)  giganteus 73 

P.  grant  i 89 

P.  granulosus  Hall 112 

P.  granulosus  Meek 109 

P.Mrrisi 180 

P.Mrudo 188 

P.  imbricatus 169 

P.  incomptus 61 

P.jamesi 146 

P.  longibrachiatus 115 

P.  matutinus 57 

P.  miamiensis 127 

P.  montanus 189 

P.  niagarensis 68, 69 

P .  obtusus 167 

P.  parviusculus 87 

P.pukJiellus 178 

P.  pygmaea. 23 

P.ruthveni 187 

P.sJiafferi - 77 

P.  simplex. 61, 62 

P.speciosus 109 

P.  spinulosus - ^ 

P.  squamatus 2s 

P.  (Monaster)  stutchburii 73 

P.  wilberanus 84 


308 


INDEX. 


P.  ?  wilsoni 106 

P.wykoffi 119 

Palaeasteridse 52, 53, 66 

Palxasterina 138, 150 

P.  antiqua 149 

P.  approximata 142 

P.  bonneyi. 153 

P.  fimbriata 204 

P.  primxva 153 

P.  speciosa 142 

Palxasterinx 66 

Palxasterinidx 138 

Palxbrisingidx 199 

Palxchinasteridx 199 

Palxgoniasteridx  (part) 66,241 

Palxgoniasteridx 128 

Palxnectria 155 

P.  devonica 155 

Palxocoma  Miller  (part) 239 

Palxocoma  Salter 252 

Palxocoma  (Bdellacoma) 254 

Palxocoma  (Rhopalocoma) 254 

P.  colvin i 253 

P.  cygnipes 253 

P.  cylindrica 220 

P.  marstoni , 253 

P.  princeps 240 

P.  pyrotechnica 254 

P.  spinosa 219 

P.  vermiformis 254 

Palaeodiscus  ferox. . 23 

Palseophiomyxa. 216, 234 

P.  grandis. 234, 235 

Palxophiomyxidx 215, 234 

Paiseophiura 235 

P.  simplex 235 

Palxophiuridx 215,216, 235 

Palaeosolaster 38, 40,207, 209,  211 

P.  gregoryi 209 

P.  (.)gyalum 210 

P.rcemeri 211 

Palseosolasteracea 163 

Palseosolasteridse 162, 163, 20  7 

Palxospondylidx 248 

Palxospondylus 261 

Palaeostella 51,138,155 

P.solida 156 

palaeozoicus,  Furcaster 259, 261 

Palxspondylus 261 

P.zitteli 262 

Palaeura 216,223 

P.neglecta 223 

Palasteracanthion 173 

Palasterina  Billings  (part) 195 

Palasterina  Salter 40, 

49, 130, 138, 140, 1 50, 154, 156, 196 

P.  bonneyi 151,152,153 

P.follmanni. , 157 

P.(f)jamesi. 146 

P.  kinahani. 155 

P.  primaeva 149, 151, 152, 153 

P.  (?)  ramseyensis 152, 154 

P.  rigidus 141 

P.  rugosa 64 

P.  stellata 196 

Palasterinacea. . .  53 


Page. 

Palasterinidae 52,53, 138, 196 

Palasteriscidae 162, 163, 199 

Palasteriscus 40, 199, 200, 252 

P.  devonicus 200 

Palastropecten 248, 261 

P.  zitteli 262 

Palmipes  antiqua 149 

papulae 16 

parviusculus,  Mesopalseaster  (?) 75, 87 

parviusculus ,  Palxaster 87 

parvulus,  Trimeraster 134 

paxillae 116,156 

peculiaris,  Cholaster 266 

pedicellariae 16 

perfectus,  Siluraster 66 

perradial 17 

petaliformis,  Jaekelaster 192 

petaloides,  A  spidosoma 243 

petaloides,  Encrinaster 243 

petaloides  goslariensis,  A  spidosoma 243 

petaloides  goslariensis,  Encrinaster 243 

Petraster 39, 

44,45,46,47,51,138,149,154,156,196 

P.  (?)  americanus 139,146 

P.  (?)  antiqua 86 

P.  bellulus 91 

P.dyeri 121 

P.  rigidus  (part) 57 

P.rigidus 139,141 

P.  smythi 139,147 

P.  speciosus 47, 139, 142 

P.  wilberianus 84 

petri,  Protaster 25 

Phanerozonia 80, 

38,39, 40, 41, 43, 44, 45, 46, 48, 51 

phylembryo  of  Stelleroidea 34 

Pisaster 38 

plates 17 

plumiformis,  Trichotaster 26, 38 

podia  and  podial  openings 18, 

17,33,38,39,209,213 

pontis,  Aspidosoma? 244 

pontis,  Encrinaster 244 

prenuntius,  Promopalseaster 104, 1 0 7 

preservation  of  starfishes 28 

primxva,  Asterias 167 

primxva,  Palxasterina 153 

primaeva,  Palasterina 149, 151, 152, 153 

primxvus,  Uraster 153 

primary  inframarginal 15 

primary  radials 1 7,  32 

primary  skeleton 13, 15, 1 7 ,  31, 32, 34, 56, 191 

primary  supramarginal 15 

primigenia,  Ophiurella 263 

primigenius,  Eospondylus 263 

primitive  starfish,  most 31,  33 

primordialis ,  Asterias 108 

primus,  Protasteracanthion 188 

princeps,  Palxocoma 240 

princeps,  Ptilonaster 240, 259 

proavitus,  Mesopalaeaster 75, 83,  85 

Promopalaeaster 28, 

39,41,42,44,45,46,47,50,56,76,98, 102, 126 

P.  bellulus 104,105,118 

P.dyeri 104,105,120 

P.exculptus 104,105,117 


INDEX. 


309 


Page. 

P.  granulosus 104, 112,113 

P.  magnificus 42, 104, 105, 106, 113, 122 

P.  prenuntius 104, 107 

P.  speciosus 104, 105, 109, 113 

P.  sp.  undet 104, 108, 109 

P,  spinulosus 44, 104, 105, 116 

P.  wilsoni 104, 106 

P.  wykoffi 42, 104, 119 

Promopalaeasteracea 53 

Promopalsesteridse 52, 53, 73 

Promopalaeasterinse 52, 74, 102 

Protaster  Hall  (part) 254 

Protaster  Forbes 216,217, 224, 229 

P.  (?)  barrisi 272 

P.  biforis 226,  722 

P.  brisingoides 236 

P.  daoulasensis 261 

P.decheni 248 

P.elegans * 221 

P.  fimbriata 231 

P.  flexuosus 231 

P.forbesi 255 

P.  (?)  granuliferus 230 

P.  (?)  gregarius '264 

P.groomi 226,227 

P.  leptosoma 237 

P.  miamiensis 233 

P.  miltoni 251 

P.  (Ophiura)  obtusus 25 

P.petri 25 

P.  (?)  salted 226,227 

P.sedgwicki 225,226,243 

P.  (?)  steUifer 226, 228 

P.  (?)  whiteavesianus 226, 227 

Protasteracanfhion 173, 178 

P.  primus 188 

Protasteridae 215 

Protasterina 228 

P.  fimbriata 231 

P.flexuosa 231 

Protoeuryale 25 

Protopalxaster 53, 56 

P.  caractad 92 

P.  narrawayi 59 

Protophiurex 246 

Protophiuroidea 213 

proximal  inframarginals 14, 16 

proximal  radials 17 

proximal  supramarginal 15 

Pseudopalasterina 138, 156 

P.foUmanni 156,157 

Ptilonaster 235,289 

P.  princeps 240, 259 

pulchella,  Urasterella. 175, 178 

pulchellus,  Palxaster 178 

pulchellus,  Stenaster 178 

Pycnopodia 38, 42, 207, 208 

pygmaea,  Palaeaster 23 

pygmaeus,  Ataxaster 161 

pyrotechnica,  Palxocoma 257 

pyrotechnica,  Rhopalocoma 254 

radial  accessory  plates 13 

radialia 17,34,35,46 

radicle  of  asterids 34 

ramosa,  Ophiura  (?) 22 

s,  Palasterina  (?) 152,154 


Page. 

ray  ambitals 13 

rays 17,38,44,48,207,213,223 

regeneration  of. 185 

regeneration 87, 185 

respiration,  see  papulae  and  csecal  pores. 

rhenana,  Asterias  (Archxasterias) 131 

rhenana,  Ophiura 263 

rhenanus,  Helianthaster 159 

rhenanus,  Medusaster 212 

rhenanus,  Miospondylus 263 

rhenanus,  Xenaster  (?) 130, 1 8 1 

Rhenaster 43, 128, 188 

R.  schwerdi 133 

Rhodostoma 236 

R.  leptosoma 237 

Rhopalocoma 248,252, 254 

R.  pyrotechnica 254 

rigidus,  Palasterina 141 

rigidus,  Petraster 57 

rigidus,  Petraster 139, 141 

Roemeraster 173, 177 

R.  (?)  acuminatus 93 

R.  asperula 188 

Roemerasterinx 172 

roemeri,  Aspidosoma 244 

roemeri,  Encrinaster 242,244 

roer  eri,  Helianthaster 209, 211 

roemeri,  Palseosolaster 211 

rugosa,  Palasterina 64 

rugosus,  Hudsonaster 36,55, 64 

ruthveni,  Palxaster 187 

ruthveni,  Uraster. 187 

ruthveni,  Urasterella 174, 175, 18  7 

SaUeraster 173,178 

S.  asperrimus 187 

salted,  Ophiura 227 

salted,  Protaster  (?) 226,227 

salted,  Stenaster 164, 166 

schlotheimii,  Acroura  (Ophiura) 18 

schlotheimii,  Ophiura 18 

schluteri,  Astropecten  (?.) 161 

schmidti,  A  spidosoma 244 

schmidti,  Encrinaster 244 

Schcenaster 202 

S.fimbriatus 204 

S.  (?)  legrandensis 206 

S.  (?)  montanus 43,207 

S.  (?)n.sp 206 

S.  ( ?)  wachsmuthi 205 

Schcenasteridse 162,163,202 

schohariae,  Taeniaster 219,220 

Schondorf,  on  revision  of  German  starfishes. .       11 

Schuchertia. 51, 140, 152, 194, 195, 252 

S.  laxata 196, 198 

S.ordinaria 196,199 

S.stellata 195,196 

Schuchertiacea 163 

Schuchertiidae 162,163,194 

schwerdi,  Rhenaster 133 

secondary  skeleton,  see  secondary  plates. 

sedgwicki,  Protaster 225, 226, 243 

selwyni,  Urasterella 175,188 

shafferi,  Mesopalajaster 44, 75, 77 

shafferi,  Palxaster 77 

Siluraster 49,53  65 

S.perfectus 66 


310 


INDEX. 


simplex,  Eoactis .  -. 186 

simplex,  Palxaster 61, 62 

simplex,  Palaeophiura 235 

simplex,  Xenaster 69 

skeleton,  secondary,  see  accessory  plates. 

sladenl,  Echinasterella 200 

smythi,  Petraster 139, 147 

Solaster 38 

solida ,  Palseostella 156 

sollasi,  Lapworthura 251 

Spanlaster 39,43,47,49,50,74,95 

S.  latiscutatus 96 

speciosa,  Palxasterina 142 

speciosus  Palxaster 109 

speciosus,  Petraster 47, 139, 142 

speciosus,  Promopalaeaster 104, 105, 109,113 

spines,  see  paxillae  and  pedicellarise. 

spinosa,  Palxocoma 219 

spinosissima,  Asterias 19 

spinosity 37,41 

spinosus,  Echinasterias 211 

spinosus,  Tgeniaster 216, 217,218, 219 

spinulosus,  Palxaster 115 

spinulosus,  Promopalaeaster 44, 104, 105, 115 

spryi,  Gregoriura 234 

Squamaster 248,249 

S.  echinatus 249 

squamatus,  Palaeaster 23 

stalk  of  primitive  starfishes 83, 34 

starfish,  most  primitive 31 , 33 

origin  of  graspers 33 

origin  of  wriggling  type 32 

radicle 34 

stellata,  Palasterina 196 

stellata,  Schuchertia 195, 1 96 

stellata,  Trentonaster 196 

SteUeroidea « 

geological  development 27,28 

geological  distribution 28 

ontogeny 36 

phylembryo 34 

typembryo 8 5, 36 

stellifer,  Protaster  (?) 226, 228 

Stenaster  (part) 173 

Stenaster 31,41,42,43,50,68,163,168,212 

S.  (?)  confluens 165,167 

S.  (?)  coronella 165,167 

S.grandis 180 

S.huxleyi 182 

S.  (?)  obtusus 165, 167 

S.pulcJiellus 178 

S.salteri 164,165 

Stenasteracea 163 

Stenasteridae 162, 168 

stone-canal,  see  madreporite. 

Strep tophiurse 215, 249 

Stiirtzaster 248,252 

S.colvini 253 

S.cygnipes 253 

S.  marstoni 253 

S.  (?)  mitchelli 254 

Stiirtzura 235,286 

S.  brisingoides 236 

S.leptosoma 236,237 

S.  leptosomoides 236,237 


Page. 

stutchburii,  Australaster  (?) 73 

stutchburii,  Monaster 73 

stutcJiburi  i,  Palaeaster  ( Monaster} 73 

supramarginalia 15, 34,35, 46 

Sympterura ;  248, 256 

S.  minveri 256 

syngnaths 218,222,224,242,256,267 

Tseniaster 216,218 

T.  australis 236 

T.  cylindricus 216,217,218,219,220 

T.elegans 219,221 

T.  meafordensis 221 

T.  schohariae 219, 220 

T.  spinosus 216,217,218, 219 

Txniasteridx 172 

Txniura 216 

T.cylindrica 220 

tenuiradiatus,  Coelaster 19 

terminals,  see  ocular  plates. 

terminology  of  Asteroidea 13 

Tetraster 31,41,42,43,50,164,165,167,212 

T.  asperrimus 187 

T.  (?)  imbricatus 168,169 

T .  sp .  ind .  Nicholson  and  E  theridge 186 

T.  wyville-thomsoni  (part) 65 

T.  wyville-thomsoni 168 

t  ischbeinianum,  Aspidosoma 244 

tischbeinianus,  Encrinaster 244 

torus 1 6,  43, 54, 174 

traquairi,  Echinostella 212 

Tremataster 246, 247 

T.  (?)  decheni 247, 248 

T.  difficilis 247 

Trentonaster 195 

T.  stellata 196 

Trichotaster  plumiformis 26, 38 

Trimeraster 44,45,50, 128, 184 

T.  parvulus 134 

trivium 14 

Trochitaster,  see  Trichotaster. 

typembryo  of  Stelleroidea 85, 36 

ulrichi,  Urasterella 37, 43, 45, 49, 175, 183 

Uranaster 61,138,154 

U.  elizse 155 

U.  kinahani 154, 155 

Uraster  hirudo 188 

U.  obtusus 167 

U.  primxvus 153 

U.ruthveni 187 

Urasterella  Sturtz 163 

Urasterella  McCoy 40, 

41,42,45,47,49,50,69,164,178,194,212 

U.  (?)asperrima 175,187 

U.  asperula 175, 188 

U.  (?)  constellata 175, 187 

U.  girvanensis 167, 175, 186 

U.  grandis 174,175,180 

U.  hirudo 175,188 

U.huxleyi 175,182 

U.  montana 175,189 

U.  n.  sp 189 

U.pulchella 175,178 

U .  ruthveni 174, 175, 1 8  7 

U.selwynl 175,188 

U.  ulrichi 37,43,45,49,175,188 


INDEX. 


811 


Page. 

Urasterellacea 163 

Urasterellidse 162,163,172 

ventral,  see  actinal. 

ventral  shield 213 

vermiformis,  Bdellacoma 254 

vermiformis,  Palxocoma 254 

vertebral  ossicles 18,213,257,267,269 

wachsmuthi,  Schoenaster  (?) 205 

whiteavesianus,  Protaster  (?) 226, 22  7 

wilberanus,  Mesopalseaster  (?) 75, 84 

wilberanus,  Palseaster 84 

Wilberianus,  Petraster 84 

wilsoni,  Palseaster  (?) 106 

wilsoni,  Promopalseaster 104, 106 

woodward!,  Eucladla 276, 27 7 

wrigglers 32,33,38 


Page. 

wykoffi,  Palseaster 119 

wykoffi,  Promopalseaster 42, 104, 1 1 9 

wyville-thomsoni,  Tetraster 65 

wyville-thomsoni,  Tetraster 168 

Xenaster 40,44,45,46,47,49,50,98,128,129 

X.  dispar 130,181 

X.elegans 130,181 

X.  eucharis 98 

X.  margaritatus  Follmann 131 

X.  margaritatus  Simonovitsch  (part) 131, 132 

X.  margaritatus  Simonovitsch 129,130, 181 

X.  (?)rhenanus 130,181 

X.  simplex 96 

Xenasteridse 52,53, 128 

zitteli,  Palseos'pondylus 262 

zitteli,  Palastropecten 262 


O 


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